The Lighting Guide

Here is a guide to lighting and light bulbs and what they will do for your plants. (feel free to suggest any changes if you see an error ) I didn't write it all.....just compiled it and added a bunch.

Indoors, 2000 lumens per sq. ft. is about as low as you want to go indoors. If you get under this mark, plant growth will definately not go as fast as possible, and internode/stem length will increase. Also, light distance to plants will be much more critical. Daily adjustments to the lamps will be necessary, meaning you get no vacations. 2500 lumens psf should be a good target, and 3000 is optimal if your going to inject or enrich CO2 levels.



High Pressure Sodium - or HPS lamps emit a pink or amber light. They are used generally for lighting parking lots and other areas where the color of the light is not all that important. HPS lights are much more efficient than MH ones, producing more light and less energy consumed. They are often used alone with no detrimental effect on the plants, and will promote faster plant growth than MH lamps during both vegetative growth and flowering. Combinations of bulbs are _NOT_ required, as the HPS lamp does produce all of the light spectrums necessary for healthy growth. There is a relatively new type of HPS lamp that has become available. It is called the...

Son Agro lamp

Basically the designers of this special lamp took a 400w HPS lamp, and added another 30W element to it, However, this new element puts out blue light, to help fill in the parts of the spectrum that a standard HPS light is missing.




Metal Halide - Metal halide (MH) lamps can be used for vegging and flowering (but primarily vegging), but there are two problems that they have when compared with high-pressure sodium (HPS) lamps. The first is that they don't emit as much total light. HPS lamps emit more than 20% more light, so MH lamps are not as intense when covering the same area. Second, they do not emit as much orange and red light as HPS lamps. These spectrums seem to promote flowering.

However, MH lamps do have several advantages over HPS. First, they are less expensive to purchase. Second, the light does not have a really weird telltale spectrum. It looks white, not pink or amber/orange.

Third, the lamps emit more UVB light than HPS lamps, although still in very small amounts. The amount of UVB light plants receive is directly related to the quality of the harvested buds. The more UVB, the higher the quality.

Buds grown under MH light will not be as big as buds grown using HPS lighting. However their quality will be as good or better.



Compact Flourescent - Or CFL . This type of light is perfect for seedlings, cuttings, and clones. They can be used for vegging and flowering but are not as effective as high intensity discharge lights like the HPS. Fluorescent lights are low intensity and need to be placed quite close (2-3 inches) to be very effective. They are a poor light source for flowering and budding primarily because of their low lumen output.

One advantage of CFLs is that they produce very little heat enabeling them to be kept quite close to the plants. But even with cool bulbs, always remember a fan for circulation. CFLs come in both warm and cool spectrums. A mix of both is ideal but warm is generally for flowering and cool for vegging. They are excellent for side lighting and can be found relatively cheap and many grocery stores and the like.



Flourescent Tubes - Fluorescent tubes have been used to cultivate and flower marijuana. However, buds grown under these lights are usually fairly small and loose. The reason for this is that the intensity of the light, that is the amount of light that is produced by these lamps, is relatively low. In addition, the light is produced over a large area. The result is a lower amount of light spread out over a large area, so the amount reaching the plants is a small fraction of the amount the plants receive from a metal halide (MH) or high pressure sodium (HPS) lamp (and even Compact varieties)

Fluorescent tubes are more expensive than HPS lamps, too. The initial cost of a fluorescent is less than a HPS. However, when the cost of light is considered the cost picture changes. HPS lamps emit 2 1/2 to 3 times the amount of light per unit of energy consumed. The efficient HPS lamp is much cheaper over its life than a fluorescent tube.

Although you can grow marijuana using a fluorescent, you will produce a much higher yield of better grade grass cheaper and easier using an HPS lamp than a fluorescent.



Incandescents - Not generally used in Marijuana growing. The common incandescent light bulb emits some of the frequencies of light the plant can use, but it also emits a high percentage of far red and infra-red light which cause the plant to concentrate its growth on the stem. This results in the plant stretching toward the light bulb until it becomes so tall and spindly that it just weakly topples over.

There are several brands of bulb type. One is the incandescent plant spot light which emits higher amounts of red and blue light than the common house light bulb. It is an improvement, but has it's drawbacks. Tbe bulb is hot, for example, and cannot be placed close to the plants.

Consequently, the plant has to stretch upwards again and is in danger of becoming too stretched and falling over. The red bands of light seem to encourage stem growth which is not desirable in growing marijuana. The idea is to encourage foliage growth for obvious reasons.




Mercury Vapor - Not generally used for marijuana growing. Mercury Vapor lamps are less efficient than the fluorescent (FL), and can not be positioned as close to the plants, so the plants will not be able to use as much of the MV light. The light distribution is not as good either. MV lamps simply are not suitable for indoor marijuana gardening. Use flourecent, MH, or HPS lamps only.



Halogen - Not generally used for marijuana growing. High pressure sodium (HPS) lamps emit at least seven times more light than halogen lamps. A garden growing under a 1000-watt HPS lamp is expected to yield one pound or more than one under a 1000-watt Halogen.

The initial cost of the halogen bulb is much cheaper than an HPS lamp. However, when the cost of generating light is considered, HPS lamps are much cheaper. For every dollar you spend on electricity for lighting using a halogen bulb, you pay only 14 cents or less using an HPS lamp.

In addition to the cost of electricity, consider the space being used and most importantly your time. You expend essentially the same effort to produce 100 grams rather than 400-500 grams. That alone makes a small harvest considerably more expensive than a large one.


I will be adding more and more detailed guides to gc have been around for a little bit and noticed tons of useful information was missing so help this helps you out guys

 

AVERAGE LIFE - The life expectancy of a lamp, based on laboratory
tests.

AMPERE (AMP) - The unit used to measure the strength of an electric current.

ARC - The luminous discharge of electricity between two electrodes in HID lighting.

ARC DISCHARGE - A transfer of electricity across two electrodes (anode and cathode), characterized by high electrode current densities and a low voltage drop at the electrode.

ARC TUBE - The enclosure which contains the luminous gases and also houses the arc.

BALLAST - An auxiliary piece of equipment designed to start and to properly control the flow of power to gas discharge light sources such as fluorescent and high intensity discharge lamps. In metal halide systems, it is composed of the transformer, capacitor and connecting wiring; sodium systems require an ignitor in addition to the transformer and capacitor.

BASE - The end of the lamp that inserts into the lamp socket.

BU - An industry code indicating that the bulb is to be operated only in a base up position.

BULB - The glass outer envelope component of an HID lamp which protects the arc tube.

BURNING POSITION - The position in which a lamp is designed to be
operated.

CAPACITOR - An electronic device that can store electrical charge. The capacitor is one of the main components of an HID lighting ballast. Because they can store a very strong electrical charge, capacitors can be very dangerous to someone who is unaware of this fact and opens a ballast in order to examine or repair it. If one does not know how to safely discharge the stored electricity, one should allow a trained technician to do any ballast repairs.

COLD START TIME - The length of time required to bring an HID lamp to 90% light output from a cold condition.

COLOUR TEMPERATURE or KELVIN TEMPERATURE - The unit of measurement to express the colour (spectrum) of light emitted by a lamp.

CONVERSION BULB - A bulb of a certain spectrum type (e.g. sodium) specially designed to operate while used in the fixture/ballast of a different type (e.g. metal halide). The most popular conversion bulbs by far are sodium conversion bulbs, which allow one to have the sodium spectrum while still using a metal halide system.

DOME - The portion of an HID outer bulb located opposite base (the neck and threads).

DOME SUPPORT - The spring-like brackets which mount the arc tube within the outer envelope (bulb).

DISCHARGE LAMP - A lamp that produces light by discharging an electric arc through a mixture of gases and gaseous metals.

ELECTRODES - Filaments located at either end of a discharge lamp that maintain an electrical arc between them.

FIXTURE - The electrical fitting used to contain the electric components of a lighting system.

FLUORESCENT LAMP - A discharge lamp in which a phosphor coating transforms ultraviolet energy into visible light. Fluorescent lamps are good for starting seedlings and rooting cuttings, but do not have enough intensity to sustain aggressive growth in plants in the later stages of life, and are not efficient enough in their conversion of electrical power to light output.

FREQUENCY - The number of waves or cycles of electromagnetic radiation per second, usually measured in Hertz (Hz).

HALOGEN LAMP - A short name for the tungsten-halogen lamp. Halogen lamps are high pressure incandescent lamps containing halogen gases such as iodine or bromine which allow the filaments to be operated at higher temperatures and higher efficacies. While excellent for home lighting and similar applications, halogen lamps are not effective or efficient as grow lights due to their very poor spectrum (extreme far red) and high operating temperatures.

(HID) HIGH-INTENSITY DISCHARGE LAMP - A general term for mercury, metal halide and high-pressure sodium lamps. HID lamps contain compact arc tubes which enclose various gases and metal salts operating at relatively high pressures and temperatures.

(HPS) HIGH-PRESSURE SODIUM LAMP - High-pressure sodium lamps operate by igniting sodium, mercury and xenon gases within a sealed ceramic arc tube. Sodium lamps emit light energy in the yellow/red/orange regions of the spectrum; the red spectrum stimulates flowering and fruit production. Many indoor gardeners switch to sodium lamps when it is time to induce flowering or fruiting of their plants.

HOOD - The reflective cover used in conjunction with an HID lamp. The more reflectivity a hood can provide, the more effective it is.

HOR - An industry code indicating that the bulb is to be operated in a horizontal position.

HOT SPOT (in this case relative to bulb and not reflective material) - The area immediately under an HID lamp where the light intensity is strongest, hot spots cause uneven growth, but can be remedied by using light movers or air-cooling the encased hood.

HOT START TIME - The length of time required to bring an HID lamp to 90% light output after a short power interruption.

IGNITOR - A component of the ballast necessary for the starting of the bulb in sodium systems.

INCANDESCENT LAMP - A light source which generates light utilizing a thin filament wire (usually of tungsten) heated to white heat by an electric current passing through it. Incandescent lamps are the most familiar type of light source, with countless application in homes, stores and other commercial settings. Light is produced by passing electric current through a thin wire filament, usually a tungsten. Incandescent lamps are totally ineffective as grow lights; they have very limited spectrum, are very inefficient in their conversion of electrical power to light output they also put off far too much heat per watt to use in horticulture, even if the above-mentioned problems did not exist.

INTENSITY - A term referring to the magnitude of light energy per unit; light intensity diminishes evenly as you get further from the source.

KELVIN TEMPERATURE (K) - The unit of measurement to express the colour (spectrum) of light emitted by a lamp; the absolute temperature of a blackbody radiator having a chromaticity equal to that of the light source. A standard clear metal halide HID lamp has an average Kelvin temperature rating of 4,000K.

KILOWATT (kW) - A unit of electric power usage equal to 1,000 watts.

KILOWATT HOUR (kWh) - A measurement of electric energy. A kilowatt hour is equal to 1,000 watts of power used over a period of one hour.

LAMP - An electrically energized source of light, commonly called a bulb or tube.

LAMP LIFE - A measure of lamp performance, as measured in median hours of burning time under ANSI test conditions.

LAMP DEPRECIATION (LD) - The decrease over time of lamp output, caused by bulb wall blackening, phosphor exhaustion, filament depreciation, and other factors.

LAMP STARTING - Generic term used to describe a discharge lamp's starting characteristics in terms of time to come to full output, flicker, etc.

LIGHT MOVER - A motorized device which moves an HID lamp back and forth across the ceiling of a grow room to provide more even distribution of the light and reduce hotspots.
LUMEN - A measurement of light output; relative to human perception
which refers to the amount of light emitted by one candle that falls on one square foot of surface located at a distance of one foot from the candle.

LUMINA IRE - A complete lighting unit, consisting of a lamp or lamps together with the components required to distribute the light, position the lamps, and connect the lamps to a power supply. Often referred to as a "fixture."

(MH) METAL HALIDE LAMP - A high-intensity-discharge lamp in which the light is produced by arcing electricity through a mixture of metal halides. The light produced by metal halide lamps is in the white-blue spectrum, which encourages vegetative growth and "bushiness" while discouraging upward growth. This is the bulb to use in the first, vegetative phase of plant growth.

(MV) MERCURY VAPOUR LAMPS - The oldest member of the HID family, mercury vapour lamps work by arcing electricity through mercury vapour. While more efficient than incandescent, halogen and fluorescent lamps, mercury vapour lamps are the least effective of the entire HID family. This, combined with an improper colour spectrum for horticultural applications, makes mercury vapour lamps a poor choice for a grow light.

MOG - Mogul base.

MOL - Maximum overall length of a lamp, from the tip of the base to the top of the bulb.

NECK - The narrow, tubular end of the HID bulb, attached to the threads.

PARABOLIC REFLECTOR - A lighting distribution control device that is designed to redirect the light from an HID lamp in a specific direction. In most applications, the parabolic device directs light down and away from the direct glare zone.

PHOTOPERIOD - The relative periods of light and dark periods within a 24-period. Also referred to as day length.

PHOTOSYNTHESIS - The growth process by which plants build chemical compounds (carbohydrates) from light energy, water and CO2 (carbon dioxide).

PHOTOTROPISM - The gravitation of a plant part toward a light source.

REFLECTOR - The term sometimes used to refer to the reflective hood of an HID lamp.

REFLECTIVITY - The measure of the reflective quality of a surface; the relative ability of a given surface to reflect light away from it without absorbing, diffusing or otherwise compromising the light's quality, intensity and spectrum.

SOCKET - The threaded, wired receptacle that an HID bulb screws into.

SON-AGRO - A sodium bulb which, according to the manufacturer, produces 30% more blue light than standard sodium bulbs. The 430-watt SON AGRO also emits 6% more light than the standard 400-watt sodium lamp.

SPECULA REFLECTION - The redirection of incident light without diffusion at an angle that is equal to and in the same plane as the angle of incidence. The secular inserts included in Hydrofarm's HID lighting systems work on this principle.

TRANSFORMER - The component in the ballast that transforms electric current from one voltage to another.

U (for UNIVERSAL) - An industry code indicating that the bulb can be operated in any position: horizontal, vertical (base up) or any other.

ULTRAVIOLET (UV) LIGHT - Light with very short wavelengths, out of the visible spectrum.

WATT (W) - A unit used to measure electric power. One watt equals one joule/second.

 

The Physical Effects of Electricity :
Electrocution or electrical shock occurs when an electric current I passes through the body. The amount of current passing through the body is determined by Ohm's Law:

I = E/R

I = Current Through the Body
E = Voltage across the body
R = Resistance of the Body

Body resistance is an important variable when considering electrocution. There is a wide variation in body resistance between people therefore the same voltage level may result in different effects. The typical human body has a hand to hand resistance (R) somewhere between 1,000 and 2,000 ohms. Babies, Children and some other people have less resistance.

The current is the controlling factor for Electrocution and Electrical Shock. The threshold for perception is about 100 microamps (0.0001 Amps). Also See Microshock Electrocution Hazards for currents less than 100 microamps. The National Electrical Code (NEC) considers 5 milliamps (0.005 Amps) to be a safe upper limit for children and adults hence the 5 milliamps GFI circuit breaker requirement for wet locations. The normal nervous system reaction to any perceptible electrical shock may cause a person to injure themselves or others, therefore the so called safe limit does not assure freedom from injury.

The more serious electrocution and shock hazards occur above the let go limits. 99% of the female population have an let go limit above 6 milliamps, with an average of 10.5 milliamps. 99% of the male population have an let go limit above 9 milliamps, with an average of 15.5 milliamps. Prolonged exposure to 60 Hz. currents greater than 18 milliamps, across the chest causes the diaphragm to contract which prevents breathing and causes the victim to suffocate. No data is available for females or children but suffocation is presumed to occur at a lower current level.

The frequency of the electrical current is as important as magnitude when evaluating electrocution and electrical shock injuries. Humans and animals are most susceptible to frequencies at 50 to 60 hertz. The internal frequency of the nerve signals controlling the heart is approximately 60 hertz. Ventricular fibrillation occurs when 60 hertz current from the electric shock interferes with the natural rhythm of the heart. The heart loses its ability to pump and death quickly follows. Ventricular fibrillation can occur at current levels as low as 30 milliamps for a two year old child and 60 milliamps for adults. Most adults will go into ventricular fibrillation at hand to hand currents below 100 milliamps (0.1 Amp).

Humans are able to withstand 10 times more current at DC and at 1000 hertz than at 50 or 60 Hz.. Electro-Surgical equipment operating above 100,000 Hertz pass high currents through the body with no effect on the heart or breathing of a patient. Do you think that Murphy's Law had anything to do with the American power line frequency being set at 60 Hertz and the frequency for the rest of the world being 50 hertz? All of the current limits referred to in the growfaq articles are based on power line frequencies of 50 or 60 hertz.

Electrocution may or may not leave physical evidence of the injury. The occurrence of burns or other skin damage is dependent upon the current density at the point where the current enters or leaves the body. Electrocutions occurring at 110 VAC seldom cause skin damage unless the point of contact is small or the victim has delicate skin. When higher voltages are involved, high currents pass through the body and there is greater likelihood that skin damage will occur. At higher voltages there are often, but not always entrance and exit wounds.


The painful truth :

This person lost the use of 3 fingers, which took over 7 months to heal.The thing that worries Overgrow / Growfaq is the fact that most people don't understand, or believe that most of the time this beast kill's and does so without warning.

Most Overgrow members wouldn't want to be put into an electric chair, but will climb into one willingly while wiring a room, opening a ballast, building their own ballasts or other devices, you name it.

Electricity can and will kill you if you don't respect it!

 

For some reason growlight manufacturers are completely ignoring the small, personal grower. A quick look around Overgrow and you can see some very respectable bud being grown under 150's, and even 70 watt HPS lights. But the smallest ready made remote ballast growlight you can buy is a 250 watter, and they usually cost well over $150 (US).

So, as usual in the medicinal herb growing world, you need to take matters into your own hands.

Here's how to turn a 150 watt HPS security light available at most Home improvment stores, into a nice remote-ballast grow light.



Materials & Tools:

MATERIALS
Regent GT150H, (About $79)
Heavy Duty extension cord of suitable length
One heavy duty grounded electrical plug end (male)
Electrical box
Electrical box plate
Romex cable connectors (3)
Wire nuts
Bolts, nuts washers
Strip of metal to secure ballast
Project case from Radio Shack ($6.99) #270-253A

TOOLS
5/16 nut driver (for removing parts from the casing -- regular pliers will work)
Philips head screwdriver
Regular screwdriver
Hammer
Power drill and assorted bits
Metal file
Wire cutters
Utility knife or wire stripper
Diagonal Pliers
Pliers

Wiring Diagram
Be careful...



Remove guts

Remove the guts from the casing - bulb socket, ignitor, light sensor socket, ballast. The ballast was glued to the casing. I heated the casing for a couple of minutes on an oven burner (high), and when it was getting too hot to hold, I put it on the floor and wedged a hammer between the ballast and casing and popped it out gently.



REMOVE LIGHT SENSOR

These security lights are designed to automatically turn on when it gets dark, so there is a built in light sensor that needs to be removed.

Remove all wire nuts.

Disconnect the white wire that comes out of the sensor (currently connected to all 3 other white wires).

Disconnect the black wire that comes out of the sensor (currently connected to the black “power in” wire).

The red wire coming out of the sensor is currently connected to the black wire coming out of the ballast. Remove the red wire, and then connect the black wire coming out of the ballast to the black “power in” wire.

Reattach wire nuts (there were 5 originally, now you only need 4).

Refer to the wiring diagram!



WIRE THE SOCKET

The socket on this particular light had some metal wiring connectors that stuck up and made it impossible to attach to the electrical plate without some modification (sorry no photo). Just pull the black and white wires off of the connectors, and cut the connectors down flush with socket base with diagonal pliers. Now loosen the connectors (screws inside the socket), slip the wires under them and tighten them back down. Please use some plastic electrical tape on the end of the socket to prevent any chance of the metal from the connectors making contact with the electrical box cover plate.

Secure the cord in the electrical box with a romex cable connector and wire it to the socket: black to black, white to white, secure with wire nuts. Some electrical boxes have a green screw inside to fasten ground wires, use that if yours has one, otherwise fasten the green ground wire to the box using one of the cover plate screws when you tighten the cover plate.



WIRE THE REMOTE BALLAST

Hopefully you can see the wiring clearly in the photo, but if not, refer to the wiring diagram for details.

You're going to have to cut some holes in the Radio Shack project box for the power cords and some bolts to hold the ballast, ignitor and ground wires down.

I used a short length of metal (plumbing department) to secure the ballast. The ignitor had a notch that made it easy to bolt down. The ground wires from both electrical cords are screwed to the base of the box.

Cut a short length off the socket (female) end of the extension cord and wire it appropriately (again - see diagram). Wire the remaining electrical cord, including the grounded male plug to the other end of the box.

Use a tie wrap to bundle up the wires in the box and try to keep them away from the ballast, which will heat up during use.



TEST IT!
If you've done everything right, it should light.



Now, build a reflector and you've got a nice little custom grow light.

Safety Warnings:
Always wire the male plug to the bulb socket and the female receptacle to the ballast to avoid possible electrocution! Always use an all metal project box which already has ventilation cooling slots, or if your project box has none, please cut adequate cooling slots, or drill several vent holes in the ballast enclosure (project box) to allow the heat to escape the box. Not adding the cooling slots or holes, could result in failure of the insulation and/or the transformer. Also, please be sure the enclosure is located in a well ventilated area to aid cooling.

 

BASIC INFORMATION
Compact fluorescents are close relatives of the 4ft tube fluorescents, commonly used in shops and schools for their white, soft light that does not cast any defined shadows. These lights are long tubes, usually 4ft long, filled with a gas that releases a photon of light when excited by electricity. The electricity is passed through the tube from the metal sections at either end, thus exciting the gas within and releasing photons of light. These lights must have a 'starter' which gets the light going initially, unlike incandescent which can just be turned on and off without one. Regular fluorescents usually emit 18w of light per tube, and cannot be plugged straight into a wall socket.

Compact fluorescents, on the other hand, are made for use in regular light sockets, and can easily be installed by anyone with basic handyman skills. Compact fluorescents are usually around 8inches long (not including the ballast, which usually adds about 3 inches to the total length) and emit minimal amounts of heat from the globe itself. Most of the heat emitted from a compact fluorescent comes from the ballast. These lights are usually between 8w and 27w, although some variation may occur between brands and uses.

The main reason people choose CF's over regular fluoro's is their compact ability! They are very 'movable' and can be positioned almost everywhere. They put out MUCH more light than their bigger cousins, while using only a fraction of the space.

Some of the many varieties of compact fluorescents.









Image contributed by: Locutus


NON-CULTIVATION USE OF COMPACT FLUORESCENTS

If you're running a large grow setup, and you're concerned about the spike in electricity, replace your regular light bulbs with compact fluoro's around the house! They give off the same light, using only a fraction of the electricity. If you're running a HID light, and the electricity increase could kill you financially, or you're just worried about LEO, it might be a good idea to replace incandescent with compact fluoro's. As an example, a 100w incandescent uses most of its energy giving off heat. If you replace all these 100w incandescent bulbs with ~20w energy saving compact fluoro's, you can dramatically reduce your energy bill, and help the environment at the same time. In fact, I recommend changing all your lights to CF's regardless of your growing situation, as they will save you $$ in the long-term, and save the environment.

The advantage with these lights is that the conversion from incandescent isn't complicated! Simply un-screw the old bulb, and screw in a compact fluoro! Done! You're on your way to energy saving paradise!


THE USE OF FLUORO'S FOR GROWING CANNABIS

Every grower has, or still uses these lights. Although they don't even come close to the results from a HID light, they do however provide a cheap alternative for a newbie 'dabbling' in the fine art of growing. Instead of spending hundreds of dollars on an HID light, a newbie can purchase a compact fluorescent for a few bucks, and still have money for a coffee on the way home.

These lights are also excellent for starting seedlings and clones, as their cool light will not dry out the soil as fast as an HID. They have a low intensity, and are gentle on newly germinated seedlings, and are great for clones as they wont dry them out or give them too much of an early blast.

Compact fluoro's are also great for stealth grows, as they can be kept about 1 inch from the plants, and do not require extensive heat ventilation due to their warm operating temperature.


WHERE CAN I PURCHASE THESE LIGHTS?

Most lighting stores will sell them, but watch out, prices are very different depending on what type of shop you get them at! As lighting shops only sell lighting equipment, their prices can either be high or low, it really depends on the type of lighting shop it is. A designer lighting shop may end up being much more expensive, as they tend to be more directed towards the upper-class designer type customer, which extra $$ to spend. Hardware's sell them, but their variety of lights is usually limited. Electricians, and assorted electrical shops will sell them, and this is most likely where you will get the best range and the best prices. My advice to you is, shop around! You wont regret it when you can save around 30% per light.


WHICH TYPE OF COMPACT FLUORESCENT LIGHT TO CHOOSE

For anyone growing cannabis, it is pointless to buy a weak light. Given the option of 8w, 15w and 27w, you would be stupid not to buy the 27watt, as they are more or less the same price. Compare the lumen output of each of the bulbs, different 27w bulbs may have different lumen outputs (depending on the manufacturer) and as with everything, the more lumens the better. You will also be given 2 options, the screw method of fitting, or the bayonet method (push and turn). My preference is the bayonet fitting. Make sure that you choose the right one for your socket! Also, do not choose a regular compact fluoro. Pick the one with the energy saving feature (will be explained why later on in the document). Now, for vegetative growth you should choose the 'cool white' light. This is also acceptable for flowering, but a 'warm white' light will be better as it is stronger in the red end of the light spectrum which is more suitable for flowering.


INSTALLING YOUR COMPACT FLUORESCENT

Now, this is extremely easy. As these bulbs fit normal light fixtures, you can just dismantle and old lamp to get the cord, plug and bulb fixture. This is ready made, as all you have to do is plug the cord into a wall outlet and screw in a bulb (with the power turned off, of course). This requires no electrical knowledge at all, and is the easiest way to get a cord suitable for a compact fluoro. The cord is simply removed from the lamp, and you are ready. If you feel you are not up to this task, or you do not have an old lamp ready to be destroyed, you can easily make one of these cords with basic electrical knowledge. Hardware's and electricians will sell you the cable (you'll need at least 1 meter) and the fittings for the wall socket and the light. Just tell them you're making a lamp for pottery and need a few cables to make up yourself. The parts are cheap, and you can save $$$ this way. If you have any queries, the electrical store will know exactly what type of cables you need etc, and will be more than happy to give you instructions on how to put it all together.

Please note that this is a guide for regular compact fluoro's. There are some outdoor varieties (which are rare) that need to be fitted specially. This FAQ is written for the regular compact fluoro's, the ones that are most accessible to the general population. Other varieties of compact fluoro's are hard to find, but may or may not be better for growing. As I have little experience with these rare lights, I cannot comment on them. The reason I haven't seen them before, is because they are almost non-existent where I live.


HOW DO I MAKE A SIMPLE REFLECTOR FOR YOUR COMPACT FLUORESCENT?

To build this reflector you will need a regular soda can, any brand will do, which you will need to rinse thoroughly until no residue is left inside. You will also need a good pair or scissor and a robust kitchen knife to cut the metal accordingly. An alternate method to remove the lid, would be to use a can opener. The lip of the lid can be used, and it will cut it cleanly. These tools should be chosen carefully as they will determine over failure or success of this construction. A lack of caution and a sharp metal edge can be fatal to your fingertips so think twice if your tools are capable of doing the job.



How and where to cut:
Firstly, draw a plan of your cutting path on the outside of the can using a permanent marker or a wax crayon. This will aid you to get a better overview of you plan and to avoid silly mistakes on the way.

Cutting the top part of the can out needs to be done first, adjusting the opening according to the size of your bulb. You do not have to cut it exactly to shape as glue (super or high-temp hot glue) can be used to stick the reflector to the bulb ballast later on. A can opener is the preffered tool for this job. The reflector is purposely not covering the ballast to ensure good aeration and to avoid damage to the ballast components, resulting in a short circuit.

Next, you will need to cut the main part of your soda can in half using your scissors. A hole may need to be drilled first using your kitchen knife to get a good starting point for the scissors.

The inside of the can is coated with a thin plastic layer that should not cause any trouble cutting through the sheet metal. The bottom side of the can does not have to remain in place but leaving it will add stability to the reflector and enhance the reflectivity. An extra hole can be cut into the bottom as well to improve ventilation along the bulb or to connect a 50mm pc-fan to the end.

Lastly, two more cuts have to be made into the sides of the semi-circle reflector to ensure that the sides do not reflect the light back to its origin but rather focus it to where it is needed. The reflector can now be bent according to your light requirements thus making it possible to focus it directly on your plants. If your reflector does not quite fit the bulb yet you can now use glue to stick it to the ballast.


HOW DO I MODIFY MY COMPACT FLUORESCENT?

The main advantages of modifying your compact fluorescent are:
· Reduced length of compact fluorescent
· Reduced heat build up (increased air-flow)
· No need for pre-made light sockets, saving you money

There is an even cheaper and more compact solution than to spend the extra cash on unnecessary light sockets and to end up with less usable space due to clumsy fixtures. All these problems can be avoided easily if one knows how to skips wiring a bulb socket and instead going straight to wiring the bulb itself. This requires some adjustments and modifications of the bulb casing but it can be done by simply following the steps provided.

For this example I will use a 23W Phillips fluoro bulb which is ideally used in confined spaces due to its compact size. The following pictures will illustrate the process of re-wiring this bulb and modifying it to meet the requirements of compact size and low cost.

This is the bulb I was referring to (23W, 1500 lumen)
Notice the upside-down “U” shaped tubes. These will require less airflow to cool the bulb as the air can move freely in between the tubes unlike those of conventional stick-like coils.




First, get a good pair of bending or clamping tongs and squeeze them tightly to the round connector plate of your CP fluoro and gently twist it off.

Never twist it off in a COMPLETE circular motion as the wires inside are still attached to the receptor plates and can sometimes break/rip if you apply too much pressure by twisting. Pulling is better than twisting. You will end up with two different wires sticking out the end. In this case, I cut the remaining plastic bit off in order to reduce the overall length of the bulb.

You will need to open the bulb ballast in order to make 2 separate holes in the plastic casing of the bulb for the two wires. This isn't hard at all, you simply need to drive a screwdriver in between the upper and the lower part of the casing and gently push them apart. There will be no glue required to stick them back together as the bulb has a push-slide-lock mechanism that simply snaps them back together. When you open the bulb, you should something similar to this even though not all ballasts are the same, depending on the manufacturer.



Now you need to drill two holes at the appropriate height for the two wires to be pulled through. Since its plastic that isn't all that hard either and can even be done with a pair of scissors.









After that, its just about putting the pieces back together and making sure the wires come through their designated hole. You can use hot glue to hold those wires in place but this is not recommended as the heat in that area of the bulb casing is very intense. Use only High-Temp glue!






If you are short of space or simply want a rigid construction, you can cut the bottom plastic part of the bulb of and use a bigger piece to distribute the weight more evenly. I used med-high temperature translucent hot glue to fit a piece of a 2” black PVC pipe onto the end of the bulb thus completely eliminating the need for a socket. This is just an optional step, as the bulb will hold without the extra support by simply gluing the sawed-off end to the predestined wall.

(ATTENTION: DO NOT USE the regular LOW TEMP Hot glue as it will melt at temperatures above 130 degrees Celsius which the bulb is capable of generating. ONLY, when gluing something DIRECTLY to the bulb casing, USE THE MEDIUM-HIGH temp. Hot glue, which will withstand significantly higher temperatures.)

Voila the final product of which you can wire as many in series or parallel as you desire. You can place these bulbs literally anywhere due their compact size and the low heat production, keeping in mind that the bare minimum between leaf tips and bulb should be 1cm (2/5 of an inch). Anything closer will result in prompt or delayed leaf burn.




This is just an example of how well suited these bulbs are for small spaces such as stealth boxes and small cloning chambers. It also illustrates the importance of ventilation as the smaller the box, the stronger the ventilation has to be to exchange the hot air buildup sufficiently.


This method is ideal for those who wish to wire a number of bulbs without spending even more money on bulb sockets. These might seem cheap when compared to the pricing of the bulb, but in the log run it is better to save a few bucks here and instead invest them in another area of growing or even another bulb. There is no need to have a possibility of replacement as the average lifetime guarantee on these bulbs lie between 10000 and 15000 hours, which means nearly two years of continuous use.

Wiring in CF's parallel:(Image by tipzijuana)




HOW MUCH LIGHT DO I NEED TO VEG CANNABIS PROPERLY?

It all depends on what light you are using, if it's HID, standard fluoro or compact fluoro (I assume you're not using halogens!). For HID (HPS or MH) lighting, use roughly 30w per square foot, and for flowering use around 60w per square foot. This is merely a guide, your plant, light height; reflective surfaces etc make a huge difference on these numbers. For a small plant, below 1ft tall, I'd say you would need at least 25w of fluorescent light. I find that it isn't at all practical to use tube fluoro's for the vegetative stage past 6 inches, as only the top of the plant is receiving enough light to carry out photosynthesis properly.

Using an energy saving compact fluoro will help 'push' the light to the base of the plant, assisting photosynthesis. If the plant indicates it needs more light by growing slowly, and with small leaf petioles, you may need more light. Go with the basic rule of keeping the fluoro's very close, and using roughly 20-30w per square foot for strong vegetative growth. If you can afford to over-light your grow room, why not? You wont regret it when your plant is bushy and healthy. If you feel that you need to only purchase a minimum amount of lights, you probably shouldn't be growing.

Growing takes effort and money, and if you can't support a plants needs you might as well just forget growing until you can afford a proper setup. Skimping on lights is the biggest mistake a grower can make, because photosynthesis is so important to for a health plant.


THE TRUTH ABOUT WATT RATINGS

When purchasing a compact fluorescent, you will notice that nearly all of them have a larger number on the box, than what it actually is. This number is the lights comparison to the brightness of a standard incandescent globe. Do not be fooled, this does not mean that the light is 100w! It is most likely around 18w.

Now, here is where the myth behind these lights is uncovered. Most people will say that you should totally discard the brightness rating. This is wrong! The brighter a light is, the more penetration it has. With a usual, run-of-the-mill compact fluorescent (say, 15w) it emits only 15w of light with poor penetration. An energy saving compact fluorescent with 15w of light, which is rated to 100w of light, will only emit 15w of light. The difference between the two is, the energy saving light has a much stronger light penetration of the normal one, while still only emitting 15w of light.

This is beneficial to growers because with a larger plant, a normal 15w compact fluoro will sufficiently light one part of the plant, and by the time the light has reached the other side of the plant, so much of the light has been lost that it is barely worth having. With the energy saving compact fluorescents, the light will travel to the other side of the plant, and still have enough intensity for reasonable results.


HANGING YOUR LIGHTS OVER YOUR PLANTS

Keep these lights under a reflector all of the time to concentrate the light onto the plant. Hang them horizontally, as most of the light is given off by the middle of the tubes. Keep them close to the plants. As a general rule of thumb, 1 inch away from the top of the plant is perfect. Any more, and you're wasting your time, and less and you risk burning your plant (although these lights are very cool, it is possible to burn your plant if it touches the light or ballast for an extended period of time). If you're given the option, go for a few compact fluoro's positioned around the plant, as opposed to 1 strong light at the top. Positioning lights around the plant help stop vertical stretching, and encourage the plant to bush out.


WHY IS A HID "BETTER" THAN A COMPACT FLUORESCENT?

HID lighting is generally accepted as a better light for growing cannabis for a few reasons...
· It has much better light penetration
· It is much more powerful (higher lumen output)
· It is stronger in light spectrums suited for growing plants

What can we do to combat these problems to make the most out of our fluoro's?

· Use a good reflector. Desk lamp reflectors are perfect, along with coke cans (cut in half from top to bottom).
· Purchase lights with high energy saving capabilities (e.g. high watt ratings)to increase light penetration
· Purchase lights with suitable spectrum strengths for each phase of growing (eg warm white, cool white etc.)
· Keep the lights close to maximize intensity

NOTES:

· For good results, these lights must be used with a good quality reflector. They give of 360 degrees of light (in a 2D cross-section) but you will only really need 90 degrees of light (maximum). Building a reflector will help concentrate all the light to the area needed, instead of wasting it lighting up the ceiling of your grow room!

· Although you can successfully grow and flower a cannabis plant under a fluorescent, your results will be poor and you will most likely be disappointed. Use these lights only for seedlings and clones, and perhaps the vegetative stage of the cycle. A HID light is recommended for flowering.

 

This is a compilation of basic information on fluorescent lighting that I have gathered over a period of several months.


artwork provided by: ReSoNiC420

What is a fluorescent light?
A fluorescent light is made up of a glass tube coated with phosphor, which is filled with a mixture of gases. When electrical current is applied, it "excites" the gases, causing the tube to glow brightly. ie: to "fluores".

Why do fluorescent lights have different colors?
The tubing is coated with phosphor, which will determine the color of the bulb.



What diameters of fluorescent tubes are available?These are the most widely used diameter fluorescent tube size is T-5, T-8 T-10, T-12. Bulb sizes (meaning diameters) vary from .25 up to 1.5 inch, the larger in diameter the larger the fluorescent.

What length is most used?
There is a wide variety of lengths from 6 to 96 inch, the most widely used is a 48 inch fixture.

What wattage is there to use?
Fluorescents come in a wide range of watts any where from 4 to 214 watts that I have found.




Why does my bulb flicker?
Fluorescent tubes are rated by hours, these hours vary by the manufacture, the most common rated hours are from 6000-22000 hrs. The bulb flickering can also be caused by a poorly seated tube (poor receptacle contacts), a ballast or starter going bad or a tube wearing out such as shown in the photograph.

How do I dispose of these lights when they are broke?
Although commercially generated fluorescent lights are required by law, to be handled separately from general trash. Residents are allowed to dispose of them with the rest of their household garbage.

Where can I purchase fluorescent tubes, and how much do they cost?
Fluorescents can be purchased at all home improvement centers, hardware stores, and most pet supply stores or you can go to internet sites such as http://www.1000bulbs.com/. The cost may vary depending were you reside, but the typical cost is a few dollar's for a pack of two bulbs.



Who manufactures these lights?
These are the most reliable companies on the market today: Sylvania, Westinghouse, General Electric.

What are lumens?
Lumens are the unit of measure that state the amount of light output produced by a light source. The higher the lumens, the greater the light output. The standard fluorescent tube should produce at least (3000-3300) lumens.

How can I optimize the light output?
You can help reflect the light out of each tube, by using metal foil tape as a reflector, attached directly to the tube as shown in this faq. click here Using clear plastic safety sleeves over the fluorescent tubes allows you to recycle the metal foil reflective tape.





What is a Kelvin scale?
One way light is measured is on a Kelvin scale. A Kelvin scale expresses the exact color the bulb emits. Bulbs in the range of 2700 to 6500 on a Kelvin scale is ideal for growing marijuana. Plants respond not only to the quantity of light, but also the quality.
* artwork provided by: ReSoNiC420 (click chart to enlarge)







What color spectrums are available in fluorescent bulbs?
Fluorescent bulbs have the most range of spectrums than any other bulb. The spectrum comes in various spectrums, determined by the type of phosphor with which the bulb is coated. The following fluorescent types are as listed, along with what they may accomplish for you.

Full spectrum fluorescent bulbs have all the colors of the Kelvin scale. This bulb is good for vegetation stage. Note: This spectrum fluorescent is used in hospitals nationwide in helping people with "depression".

Wide spectrum fluorescent bulbs will restrict development of side branching, helps plants mature faster. This fluorescent is high in the red, orange and yellow color range. In fact, this fluorescent is the highest than all other fluorescent bulbs. As a matter of fact, this fluorescent is much like an HPS color range, which makes it the best all around choice for flowering stage.

Daylight spectrum fluorescent bulbs are very high (if not the highest) in the blue range on the Kelvin scale. This fluorescent promotes an arctic blue look. I suggest this fluorescent during vegetation stage.

Cool spectrum fluorescent bulbs will promote multiple side growth, nice green foliage. This fluorescent is high in the blue range, giving off a bright white appearance. I suggest this fluorescent for vegetation stage.

Warm spectrum fluorescent, will promote extra thick stems and branches, and will give you about 5% denser buds than other spectrums. This fluorescent is high in the red range on the Kelvin scale.

In the old school of fluorescent growing, an even mix of warm white and cool white tubes has been proven to be the best combination of light spectrums to use for flowering stage. If wide spectrum bulbs are unavailable in your area, then this is the combo to use.





Do fluorescent tubes need air circulation? Fluorescent tubes do get warm, but not if they have adequate air circulation. A simple fan blowing over the fixtures as shown, will help a great deal to cool the tubes.
If its done properly, any stray foliage that comes in contact with the tubes will not be harmed.

 

In a shop light type fixture, the bulbs are usually space a few inches apart. This type of reflector creates light "stripes" when used close to the plants. The hood on a shop light helps to widen the light by reflecting the light coming from the top of the bulb. When you use this style reflector the light never leaves the top the bulb, instead its reflected back through the bulbs and sent out the front. If you doubt this works check with any aquarium shop and ask them.

The foil reflector: when you want the bulbs close to one another.

OK, all you need is a bulb and some 2” wide foil tape. Now, cut the tape so it is a couple of inches shorter than the bulb. This is for two reasons. First, the bulbs get hottest on the ends (heat can make the glue release and the ends of the tape will pull up). Second, it keeps the conductive foil away from the power at the end.

Before you start sticking the tape on, make SURE you have the bulb laying where the pins are horizontal to the floor. If your pins lock at an angle in the fixture, make appropriate compensations.

* Make sure you get the tape oriented with the correct florescent pin position when installed!*

Now start the tape about an inch from an end, and let the center on the tape stick to the very top the bulb. Keeping the tape straight, slowly run it down to the end. Tear off any excess at the end before sticking it past the last inch. Be sure to keep tension on the tape as you lay it - it helps to keeps the tape straight and centered (stops wrinkles).

Now that the center of the tape is stuck, start at the middle of the bulb and slowly make the tape touch a little more from the center out so that the tape is starting to take shape of the bulb. Work from the middle to end of the bulb. Don't try to get all the tape to stick in one try. The tape will not lift once set in place.

Note: trying to stretch a full length of foil tape and trying to lay it all-at-once onto the bulb is extremely difficult; if the tape touches anything it'll stick hard, and it tends to curl when you peel off the backing.

The results:

I took a comparison picture. The taped bulb is brighter and the light is focused downward. You still have some side lighting but as you can tell it is much less. The last picture is of a bulb that is over 30 days old and it shows no sign of phosphorous burning, stress or damage.

Using this technique you can literally create a wall of light. Floro's are not known for their power, so be sure to get all the light you can get out of them.


Editors Note: If your foil tape doesn't have clear adhesive, mylar can be used in it's place.

 

Adding Glass Shields to HPS reflectors

1. First of all, you'll need a Reflector with HPS of course I think that way of adding glass will be suitable for many kind of reflectors.

[Editor's note: Venus has used a batwing, but this technique can be used on many different shapes of reflectors, as long as there is adequate clearance between the bulb and glass. Large 1000w MH bulbs may not fit inside glass-enclosed reflectors]



2. That is all u need: Pliers, Sidecutter, "Philips" screwdriver, 5mm bit for making holes in reflector, 4 bolts, 4 "L" shaped brackets, a ruler, electric drill and isolating band (rubber/elastic tape). Note the bolts and "L" shaped brackets that I used.






3. Now, to make this done u will need a peace of glass. Take the ruler and measure the size of glass u will need. Hardware stores, windows shops, etc will cut any type of glass you want. Bring your measurements. I used regular, 1/8 (3 mm) window glass. Here is the peace they cut for me using sizes I gave them.

[Editor's note: most window/glass stores can make fabricate/cut tempered glass (high heat resistance, thin & light, but high cost), or regular plate glass (lower cost).

Tempered glass is preferrable for high wattage lamps, as their heat is extreme. Plate glass can crack under these hot conditions.]


4. Take the electric drill and drill 4 holes in each corner of the reflector. To make this, I used a 5mm bit.









5. Take the isolating band and cut it with scissors in half......I doing this because the width of the iso-band is more wider than the "L" shaped bracket. Now ,take that half cut iso-band and just roll over the "L" shaped bracket. That way, the glass will sit on a soft surface instead of a metal surface - protecting it against scratches, vibrations and slip over...





6. Take the bolts & brackets and screw them all together to the reflector......

Then, flip over the reflector and slide the peace of glass into it.

Here u can see how it will look with the glass sitting on the brackets and just below the bulb......I kept 1.5 inch (4 cm) between the glass and bulb.





7. After all dirty work is done, the final product looks gorgeous and will do the job it was intended to do......

With all stuff prepared before doing the job ,yuo can finish all this in about an hour ....

 

Configuration
This type of fixture is very versatile. There are many different ways it can be configured:

*hanging or mounted on a chamber wall
*open-ended drawing air from the grow or ducted to a separate intake
*passively or actively cooled

Tools Needed:
*Power drill with 1/8" or 3/16" drill bit
*4.25" hole saw
*pop rivet gun (optional)
*flat head and Phillips head screw drivers


Materials:
Keep in mind that the full list of materials you will need depends on the type of glass you get and the configuration you're looking to build. Here's the materials list with some pictures and approximate pricing:

· $3.99-- Glass, either 4" Pyrex tube (approx. 12" long, 4” diameter) or "hurricane" lamp glass ($3.99 at Hobby Lobby, is 11 3/4" long and 4 5/8")
· $2.99-- 4" H/C venting starter collar
· $4.50-- 5" to 4" venting pipe reducer (for use with hurricane glass only)
· $3.00-7.00-- High-temp foil tape
· $5.00-- Thermal pipe wrap (looks like woven fiberglass tape with no adhesive)
· $8.00-- 4" aluminum "dryer" ducting (hanging configuration)
· $2.00-- 1/2 wood screws (box wall mount only)
· $3.00-- pop rivets or small sheet metal screws
· 4" (dryer ducting and/or Pyrex tube only) and/or 5" (hurricane glass only) hose clamps
· "S" hooks (for hanging)

a. Hurricane glass tube

When working with the hurricane glass "chimney," the irregular shape needs to be overcome so that it can be attached it to a reducer collar that will make up one end of the fixture. You may attach a reducer collar to a single end if you want an open ended design, or you can attach one to each end if you will be running ducting to both intake and exhaust ports.

The graphics concentrate on the exhaust end to which the bulb socket is also anchored. On this end of the glass (at the narrow "throat") numerous wraps of thermal pipe wrapping are wound around the glass and secured with a couple of wrappings of foil duct tape. The wrapping should build up the throat to the same diameter as the opening in the glass - where it snugly fits inside the larger end of the reducer.



This will allow us to use a 5" hose clamp to secure the edge of the reducer collar to this tape wrapped "cushion." (Note: you can use foil tape alone for building this "cushion" but the thermal wrapping makes for a neater seal, and is less susceptible to heat. Also, if a hose clamp isn't available, the reducer can be secured to the glass with foil tape.

If you use a hose clamp, you will need to make some 1" slits in the edge of the reducer collar the glass fits in to allow the hose clamp to compress it enough to hold the glass securely)

Mounting the socket inside the tube
In the graphic, a length of pipe strapping bent in a "U" shape is used to hold the socket far enough inside the glass to place the bulb roughly in the middle of the glass. This glass, $3.99 at Hobby Lobby, is 11 3/4" long and 4 5/8" at each end. Notice this glass is symmetrical. Don't try to use the asymmetrical hurricane lamp "chimney's" available at Lowe's or HD; they're too small and aren't shaped in a way that permits good air flow.

The socket is either screwed or pop riveted to the bottom of the pipe strap "U." My light was made from a 150w HPS security light which used a "medium" base socket; this socket has two little screws in it that more or less lined up with the holes in the strapping.

As for the mogul base sockets used with bigger lamps, I don't know what they have on the bottom of them so you may have to improvise a solution for mounting them. The ends of the strap are bent around to "clip" over the edge of the glass and then secured with a couple of wrappings of foil tape. If you'd like, a more permanent mount can be had by drilling a couple of small holes in the tapered throat of the reducer and attaching the ends of the strap with a couple of pop rivets.

Running the wires
The wires from the socket can be either run through your 4" ducting which will attach to the other end of the reducer or you can drill a hole in the tapered part of the reducer to run the wire out of the fixture to the ballast.

Here's how I actually have it done in my box. There's no venting, it just mounts to a 4.25" hole in the side of my flowering chamber via a starter collar which fits snugly inside the 4" side of the reducer collar. I've got them held together with four pop rivets for a permanent connection. The tabbed end of the starter collar fits into the hole where the tabs are bent around the edge of the hole and anchored with wood screw to the box wall. (In my box, on the other side of this wall is my utility room with a 4" 115cfm computer case fan sucking out the back of it.)

One could just as easily connect another reducer collar onto the other end of the glass exactly as the first side was with "S" hooks for hanging from above. This fixture could then have both intake and exhaust from outside the box.

Originally this is what I would have preferred to have, but as my flowering chamber is only 2'Dx2'Wx3'H, the wall mount actually did better for me.

johnstone- Hurricane tube NIMBY - Baking tube
b. Pyrex baking tube

(NIMBY) "Using a Pyrex (borosilicate glass) tube obtained from a glass blowing supply house or using a "Bake a Round" (eBay had a dozen for sale the last time I checked) one utilizes either one or two (pictured) 4" starter collars instead of the 5" to 4" reducer collars. They are 14" long and 3.75" in diameter."



"I stretched the aluminum ducting out and measured 16". I then snipped the metal "ribs" and cut the ducting open. The glass tube will now just drop into the long run of ducting. The electrial wires run to the remote ballast through the intake part of the duct (exhaust could also be used depending upon the location of the ballast). I measured 2" from each side of my original cut and snipped the metal ribs again but this time didn't cut the aluminum foil. This allows me to open the ducting up like a "wing"."



A couple of wraps of pipe wrap sealed with foil tape on each end you want to put a collar on should be used to keep from biting the metal directly into glass with the hose clamp (pictured). The socket is mounted inside the tube with pipe strapping just as in the hurricane style fixture. It can either be "clipped" and taped over the edge of the glass or better, pop riveted to the inside of the starter collar.

Simply stick the glass inside the end of the starter collar an inch or so past the bottom of the tabs to measure how far in to drill two holes 180 degrees apart, then use two pop rivets to attach the strapping

A note about pipe strapping: don't get the thin wimpy stuff. Get the thicker heavy-duty strapping. The heavy stuff is still relatively easy to bend but holds it's shape better and will hold the bulb and socket straight without sagging. At Home Depot they even have some copper pipe strapping (also known as “pipe tape" or “pipe hanger”) that is quite stiff.

Ventilation Performance
There are many different ventilation options available, since standard household ducting is used in the construction of the fixture. For those folks with bigger boxes or rooms, ducting in and out, "inline" duct fans are probably the best option.

For my little NewGanjaBoy-style setup, using the Hurricane fixture as part of the ventilation system of my box, a 115cfm computer fan does the trick. As for actual performance specs for different blowers/fans and light wattages, I'm afraid you'll have to experiment. Here's mine just to give an example:

Box:
-NewGanjaBoy-style three chambered box
-4 20w flouros in the mother chamber
-150w security HPS in the flowering chamber in original metal fixture with holes drilled in the top

Ventilation before Cool Tube installed:
-115cfm fan exhausting box
-4"x8" intake port in the bottom of the veg chamber
-Two 2' runs of 1.5" PVC pulling air through the wall between veg and flowering chambers
-Two 1' runs of 1.5" PVC pulling air from over the HPS fixture into the utility room where it's exhausting out the back.

Ventilation after Cool Tube installed:
-Two PVC runs between flowering chamber and utility room replaced with Hurricane Cool tube fixture
-ballast moved to utility room and housed in the original security light casing
-everything else is the same

Temps before Cool Tube mod:
Ambient temp: 80F
Flowering chamber 1 hour after HPS fires up: 95F (in direct light)
Flowering chamber 6-12 hours after HPS fires up: 100-105+F (ouch!!)

Temps after Cool Tube Mod:
Ambient temp: 80F
Flowering chamber 1 hour after HPS fires up: 85F (in direct light)
Flowering chamber 6-12 hours after HPS fires up: 90F (in direct light)

SAFETY NOTICE:
Please note that the wire to the bulb base must be a high temp fiberglass type, or the heat will eat up the wire and cause a running short. The thermal tape is a fiberglass electrical tape from most hardware stores. High temp fiberglass wrapped wire is available at any hardware or electrical store. It is imperative that you use it, as a smoking ballast is a real bummer to relight.

 

For (artificial) light, there is a law that always applies known as the Inverse Square Law. It states that light diminishes exponentially in energy as the distance is increased from the source.

A good example is that you might be getting 1000 PAR Watts at 4" from your light source, but that would change to 250 PAR Watts at double the distance (8"). This law makes it EXTREMELY important for indoor plant growers to get their light source as close as possible to their plants. The amount of light your plant receives is directly related to it's yield/flower density.

The problem: Indoor lamps used for plant cultivation (HID - High Intensity Discharge) give off large amounts of heat, to such a degree that they could cause damage to the plant if put too close.

Indoors, there is an optimum distance/height between the plants and the light source. This distance fully illuminates the whole canopy with direct light from the source, but is as close as possible to the plants for maximum lumen intensity. This will be called the OLH, for Optimum Lamp Height.

Ultimately, to get the best light efficiency from your lamp, you want it at the OLH at all costs. But how can you get it there without causing harm to your plants with the abundant heat?

First, try moving your light to the OLH and see what it does to your plants. If they have no problem, then you're fine. If you have a high output HID, this probably won't be enough.

Next, try actively exhausting your light hood by hooking up a direct exhaust system to the hood, and then move your lamp to the OLH and see if the plants are O.K. If the plants still seemed affected by the heat, then you must add glass to your actively exhausted lamp hood. Glass will absorb/reflect/filter some of the light energy being emitted by the lamp.

The number would seem relatively low, around 2-3% of PAR wattage, but it will effectively filter out almost all of what little UV-B is emmitted by the lamp. UV-B is believed, and has been shown, to have a positive influence on the potency of Cannabis.

Overall, it would be beneficial for one to add glass if needed to keep their lamp at the OLH, due to the all-powerful Inverse Square Law; moving light farther away will greatly reduce the amount of energy being emitted and is reaching your plants (Light intensity is directly related to yield and flower density).

Almost all glass offered today for insertion in air-cooled lamp hoods is tempered glass, which is regular glass with low amounts of impurities. If one was looking for the most efficient glass for their hood, quartz glass will allow the transmission of UV-B, but is not made specifically for light hoods.

And also remember, that if you have a rectangular garden, it is important to position the longest side of the reflector parallel to the shortest side of your garden. (from FAQ by Head Rush)

Additional note: you should periodically inspect and clean your light hood and bulbs, especially after foliar feeding or underleaf spraying for insects. The dust and dirt that collects will definitely decrease reflectivity. Isopropanol alcohol, glass cleaner or water (and a soft cloth) can all be used to remove streaks, dust and spots.

Contributed by: MedMan

There are a number of factors which play a part in the temperature radiated from your bulb, watts, hood design and air circulation for example.

A simple method of testing for temperature is to use the back of your hand; if its too hot for your hand, its too hot for your plants. Good ventilation is the key to getting your light closer to the garden.

Editor's note:

Recommended typical OLH distances:

Flourescents: proximimty
400w HPS: 1 foot
600w HPS: 1.5 foot
1000w HPS: 2 foot

 

It has long been known that the green part of plants, when exposed to light under suitable conditions of temperature and water supply, intake carbon dioxide from the atmosphere and release oxygen into it. This gaseous exchange is the result of photosynthesis. The intensity, quality and daily duration of illumination all influence the amount of photosynthesis that takes place.

Each type of plant, whether it's sun-loving or shade-tolerant, has its own rate of photosynthesis. More photosynthesis appears to occur in the orange, short red and blue bands of the spectrum than in the green and yellow bands. In general, the longer the daily amount of illumination, the more photosynthesis will take place.

 

Ballast Wiring

One of the best ways to save a bundle on equipment is to wire up your own lights from a kit. By buying the parts unassembled, you can probably construct a light for half of what it would cost "ready made" from a hydro shop. As well as saving money, you can avoid the paranoia involved in shopping there. Many people might be reluctant to work with wires and electricity, which is certainly understandable, But it isn't nearly as difficult as you might think.

Let's examine what is inside a ballast. There really isn't much depending on which type of light you buy. An high pressure sodium (HPS) ballast consists of 3 parts: The transformer, the capacitor, and the ignitor. A metal halide (MH) ballast generally has just the transformer and capacitor.

Every single one of these parts is available at pretty much any lighting or electrical supply warehouse, including the bulb and socket. Break out the phone book and look in the yellow pages under "lighting". Call them and ask if they carry "Transformer, capacitor, ignitor (if for HPS), and socket" for whatever size bulb you wish to use (150, 400, 1000 etc.) and type (Metal halide or High pressure sodium) light you wish to purchase. Odds are, they will have it. If not, try another store until you find the one which has what you want. You can also order this stuff from many online electrical supply places. There is virtually no worry about having this stuff shipped to your house, since it did not come from a "high profile" hydro shop.

When you purchase your ballast components, be sure to buy the correct line voltage rating you intend to operate it on. Most homes in the US are wired for 120 volts. If your house happens to have a different voltage (IE: 210) then you need the corresponding ballast parts.

Another option is to purchase what is known as a "multi-tap" ballast. This type of ballast has a wire connection which can be changed to allow several optional voltages. Some stores may only carry multi-tap ballasts to save money on inventory. A multi-tap ballast will work fine in any situation. Multi-tap ballasts usually have the following options inside: 120/208/240 and 277 volts.

Besides the transformer, ignitor, capacitor, bulb and socket, you are going to also need the following: About 20 feet of 14(or better) gauge wire, a male plug set, about 8 wire nuts.

The wire and the plug are for installing the power cord and socket to your ballast. You can also simply buy a long heavy duty extension cord, which you then will cut up. Whatever wire you buy, make sure it is rated to at least 15 amps and 1500 watts (14 gauge). That size is good for wiring all the way up to 1000W lights.

Now, when you get your parts, you will also likely get a wiring diagram. It may come on a separate sheet of paper, but more than likely it will be on a label on the transformer.

I have added a few descriptions for the sake of clarity, but the basic schematic is the same. This is for a HPS lamp and describes the wiring for the 3 internal components and socket. For some people, the schematic may be a little confusing. Let's take a look at the same thing but in a “real time" photograph, instead of the diagram.



You can clearly see all of the components you will be dealing with and how they will be wired together. Let's examine some of the more important points.

If you look at the transformer, you can see it is labeled as having a "short side" and a "Long side". These are my descriptions for the two different areas of the transformer. If you look carefully you will see that the transformer has two protuberances where wires come out. One of them is thicker than the other. That is the "long side". It is important to know the difference when you're wiring it. The capacitor is a simple affair with just 2 wires.

The ignitor has 3 wires. Look closely at the wires running from the socket. You can see that each of them comes to a junction with two other wires. All 3 wires at a junction(and at all junction points for all wires) are held together using a "wire nut". This is just a plastic cap which screws onto wires to hold them together. Make all the wire connections using wire nuts, do not use tape.

Although you can't see it, all wires have something printed on them so you can identify them. It is going to be something numerical("X1","120") or alphabetical ("lamp", "com"). In my example, wires are noted with X1 or X2 or , other ballast kits may have wires which simply say "one" or "Two" and "volts"(instead of "120"). Sometimes wires are colored ( the ignitor wires in my example are red blue and white) sometimes not. When wiring a ballast, don't get mislead by the color of wires on the ignitor, capacitor or transformer. These wires are connected according to what is written on them, not by color. Color will only come into play when dealing with wires coming from your power cord and socket. These are going to simply be black, white and green with no labeling.


High Pressure Sodium (HPS)
This wiring description is for an advance brand ballast. If you end up with a different brand and the wiring doesn't seem quite the same, then it isn't. But should not be very difficult to figure out the difference after familiarizing yourself with the various wires and parts in the illustrations.

First, orient the transformer so that you know which side is "long" and which is "short". Locate the 2 wires that say "cap" on them. They should be coming from the inside of the transformer bulges. These wires all either get connected directly to the capacitor using connectors or by soldering, or with wire nuts to the wires coming from the capacitor.

Next, locate the wire coming from the long side of the transformer which is labeled somewhere with the number 3(or ""). Then with a wire nut, connect it to the number 3 wire coming from the ignitor. Make sure the nut goes down snugly and that no bare wire can be seen.

Before going any further, you need to figure out how far from the ballast the bulb will be placed. In my example, the wires to the socket are only a foot long so that I could get it in the picture. In real life, the wires will usually be 6 to 10 feet long. Use a piece of heavy duty (extension cord) wire and wire nuts to extend the socket's wires as far as you need to. Just attach black to black, and white to white. The green wire is a ground which will get attached to your reflector on one end, and to the transformer base/ballast box on the other end to safeguard against shock.

Then, find the white wire labeled "com X2" (or "com2" or whatever it is in your particular case) coming from the transformer's short side, the #2 wire from the ignitor (it may also say "com X2" or "com2" or simply "2"), and the white wire from the socket. Connect all three of these wires together using a wire nut. Make sure the connection is tight with no bare wire showing.

Find the wire coming from the transformer's long side labeled "lamp". Along with the #1 ("X1" or "1") wire from the ignitor and the black wire from the socket. As above, connect all 3 wires together with a wire nut.

OK, you're almost done! The last two wires should come from the transformer's short side. One should say "com" and the other "120". These are the two wires that will go to your power cord. Cut the extension cord to the right size and trim away the outer insulation to expose the three wires (white, black and green).

The white wire gets connected to the "com" wire on the transformer, while the black wire goes with the "120" (or whichever voltage you have) on the transformer. The green wire is the ground and that gets attached to either the ballast box or the base of the transformer to safeguard against shock.

If you bought a multi-tap ballast, now is the time to deal with that. There should be a wire with a connector clip on it attached to 1 of 4 possible spots on the transformer. These 4 options are for 4 different voltages. Find the one labeled "120" (or whatever your voltage is) and attach the wire/clip to that one. Some ballasts simply have a few extra wires inside labeled for different voltages. In that case, find the one for your voltage and strip the insulation off the end, then connect it with a wire nut to the black from the power cord. Make sure to leave the other voltage wires with all their insulation. For safety's sake, cover each of the unused wires (individually) using a spare wire nut for each one to insulate them.


Metal Halide (MH)
If you want a metal halide light, your task is even easier because now you only have the transformer and capacitor to work with and no ignitor. This is for standard metal halide ballasts. On occasion, you run into a MH ballast which has an ignitor. Try not to get this kind if you can. If this is the only option, then follow the instructions for HPS ballasts.

Connect the wire labeled "cap" coming from the transformer's long side to the capacitor. Connect the other wire coming from the capacitor (labeled "lamp") to the black socket wire.

The transformers short side will either have 1 or 2 wires coming from it labeled "com". If there is only one, then connect that wire with both the socket's white wire and the power cord's white wire. If there are 2 "com" wires, then pick one and connect it to the socket's white wire. Then connect the other "com" wire to the power cord's white wire. Connect the power cord's black wire to the transformer's short side wire labeled "volts" or "120"(or whatever voltage you have).


Testing
Now, even though it will work without it (and even though it got left out of all the illustrations), I recommend grounding the socket and power cords. The grounds are the green wires coming from these 2 cords. Both of these wires should be attached either to the metal base of the transformer or to the inside of the ballast box if it is made of metal. The other end of the socket ground gets attached to the metal part of the reflector. Double check everything. Screw the bulb in the socket, then plug in the power cord. The ballast should hum and the bulb should come on almost immediately. If it doesn't or if you see or hear anything unusual, unplug it.

Most likely, if you made a mistake, then the bulb simply will not light. Always wait five to ten minutes before touching any of the wires after unplugging the unit. This is because the capacitor holds electricity and you may get shocked if you touch the wrong wire. Double check everything again.

A quick word about the bulbs. While all HPS bulbs can burn in any position, a MH bulb must be purchased specific to the mounting position you intend to use. There are MH bulbs made specifically for horizontal placement, base-up placement, vertical (base down) placement and also universal placement. The universal type bulbs can burn in any position, but are not quite as bright (maybe 5% less) as the position specific bulbs.

 

Introduction

Lighting is a very important component of your grow. You could have the best genetics, the perfect growing space, and tons of knowledge, but without adequate lighting, your grow will simply not perform. This article is not in any way designed to dissuade a person from using fluorescents or MH. This faq is a guide for those that would like to know more about HPS lighting systems and how to buy, assemble, and use them.

Pre-assembled HPS lighting systems can be expensive. Most of the cost is overhead and labor. If you were to buy the components separately and put it together yourself, you can save hundreds of dollars with only a small amount of quality sacrifice. Also, when you build it yourself, you have a wider range of products to choose from, so you can build a system that is right for your situation.

Planning

The first step in building a system is to know exactly how much light you need for your area. This FAQ will give you an idea of what you will need to buy: ********


Parts required:

· ballast w/ igniter and capacitor
· socket
· bulb
· extension cord w/ ground wire

OPTIONAL
· reflector
· ballast case
· air-cooling

TOOLS
· screwdriver
· wire cutters and strippers
· wire nuts
· electrical tape

Obtaining parts

To begin on your quest you will need to shop around places in order to find the best deals. You can order the parts you need from the Internet, or you can buy them at a local electrical store. We will discuss Internet purchasing later on.

Many of you that live in larger cities will be able to call around to many electrical stores that will carry HPS ballasts and do some comparison shopping. Those in smaller cities might not have a great selection. If you look in the phone book under electrical suppliers, you will see wholesale and retail suppliers. You can get prices from both, but when you call the wholesale store, you will have to ask them if you can buy without an account. Going with the wholesale store will most likely be the cheapest, as they will have many types of ballast in stock. It is important that you ask them if you can buy them individually.

Also, you will need to know exactly what you want. You can buy 70 and 150w HPS at Lowe's or Home Depot, so I am going to concentrate more on 200w and up. The available wattages are 200, 250, 400, 430, 600, and 1000. You will need to determine what voltage you are going to be using (household current in the US is 120v). It is very important that you buy a ballast kit that is compatible with the voltage in your house. Most places will sale multi-tap ballasts which have higher voltages along with the standard 120v. This will probably be your best bet.

If you wish to order online, there are plenty of stores that you can choose from. You might also want to do searches on google to find other deals.

Purchasing

From store:
· Pay in cash, nothing with your name on it (no paper trail)
· Act calm and confident. If you act shady, they might report your license to the authorities.

· Know what you are going to buy before you get there, so you can just walk up and ask for it.

Online:
· Make sure that company sends the packaging in discrete packaging. Nothing with Hydro, Horticultural, or any other growing references. This will help ensure that your package will not be watched. This is also good if you are getting it shipped where people will not know of your operation.
· Always make sure you check out the return policy on damaged and non-operational equipment.


For my example, we will put together a 400w HPS lighting system: (example prices)

· ballast (400w includes igniter and capacitor) $69.29
· porcelain mogul socket $13.20
· bulb (There are many different bulbs, each with different spectrums. This is a cheap bulb) $16.15
· 20' extension cord (length will vary) $8.00
· wire nuts and electrical tape (estimate) $4.00)
TOTAL: $110.44

Accessories. Reflectors are not necessary, but even a cheap batwing style reflector will benefit you by directing the light where you want it. Ballast boxes are also not necessary, but having one reduces the risk of electric shock, burning, and fire.

Optional parts
· reflector(batwing) $30.37
· batwing reflector $21.67
TOTAL: $52.04

Grand total: $162.48 + shipping

The items listed above will give you a fully functional HPS system that is much like one that you can buy.

If that price is too high, the reflector and ballast box are expendable. You can make your own reflector and you can mount the ballast on just about anything that can take screws. Doing so, introduces the risk of you touching the ballast components and getting burned or shocked. As long as caution is exercised, you have nothing to worry about.

Additional Options

Air-cooling is another option that people would like to look into more often. Having separate ventilation for your lights will ultimately benefit you as you will have more head room for your plants to grow and the temperature will be greatly reduced.

There are 2 method of obtaining an air-cooled reflector/hood:

1) You can build your own using:
· This FAQ on how to build an air-cooled hood, with integrated carbon scrubber, and light trap (for the true DIYer)
· This FAQ on how to build a cool tube *recently updated
Note: If you are going to make the cool tube from above, you can hang the cool tube assembly underneath a stationary reflector, which can either be homemade or manufactured.

2) You can buy a complete air cooled hood online, or at hydro stores


Assembly

Now that we have all the parts that we need, we need to wire up the ballast and assemble the light together. I will point you to this FAQ that taught me how to wire my first ballast. http://www.overgrow.com/growfaq/966

Connector plugs

A good way to connect the socket to the ballast is to install a set of connector plugs between the ballast and the socket. This will enable you to disconnect and move the light without having to disturb your wiring. Also, you can locate the ballast in another area as to keep heat down in you grow area.

Take a 10' - 15' extension cord and cut it into 2 lengths. The shorter one should be the male end (the one with the prongs) and the longer one should be the female (the one with the holes). You will probably want to have the shorter one be around one foot long. It is the piece that is going to be connected to the socket/bulb assembly. The longer piece will need to be long enough that it can reach the other piece of cord from wherever you are going to place the ballast.

Note: We attach the ballast to the female side in order to reduce danger of electric shock. In a rush to pull apart the set up, a person might leave the ballast on and accidentally touch the prongs on the wire. Trust me; you don't want to get shocked by a ballast of any wattage.

Connect the white wire from the male end of the extension cord to the white wire of the socket. Connect the black wire of the extension cord to the black wire of the socket. Connect the green wire, if you bought a socket that has a grounding terminal.

You will want to connect the female plug to the ballast. Connect the white or COM wire that is coming out of the igniter to the white wire of the extension cord. Connect the black wire from the extension cord to the RED or X2 wire coming from the igniter. You can also connect the green (ground) wire to the same place that you grounded your ballast.

Additional Information

LIGHT SAFETY

· Remember not to spray water on or near an exposed HPS light bulb, especially when its on (foliar feeding may cause the bulb to explode if water touches the bulb)!
· Do not look directly into the HPS for any amount of time. If you are going to be in your grow room for a long amount of time, wear sunglasses
· Do not touch an HPS bulb while it is hot · Do not touch an HPS ballast while it is hot
· Replace your lights every 10000 to 15000 hours

 

Yes Ballasts and Bulbs Should be Matched.

HID bulbs generally need specific ballasts, and any given ballast can usually safely and effectively operate only one type or a few types of HID bulbs.

The bulb wattage must be matched to the ballast. A smaller bulb will usually be fed a wattage close to what the proper bulb takes, and will generally overheat and may catastrophically fail. Any catastrophic failures may not necessarily happen quickly. A larger bulb will be underpowered, and will operate at reduced efficiency and may have a shortened lifetime. The ballast may also overheat from prolonged operation with an oversized bulb that fails to warm.

Even if the ballast and bulb wattages match, substitutions can be limited by various factors including but not limited to different operating voltages for different bulbs. Examples are:

Pulse-start sodium lamps often have a slightly lower operating voltage than metal halide and mercury lamps of the same wattage, and ballasts for these sodium bulbs provide slightly more current than mercury and metal halide ballasts for the same wattage would. The higher current provided by the pulse-start sodium ballast can overheat mercury and metal halide lamps. Mercury and metal halide lamps may also "cycle" on and off in lower voltage sodium ballasts, such as many 50 to 100 watt ones.

Metal halide lamps have an operating voltage close to that of mercury lamps in many wattages, but have stricter tolerances for wattage and current waveform. Metal halides also usually need a higher starting voltage. Most metal halide lamps 100 watts or smaller require a high voltage starting pulse around or even over 1,000 volts.
175 to 400 watt metal halide lamp ballasts can power mercury lamps of the same wattage, but the reverse is not recommended.

Mercury lamps 50 to 100 watts will work on metal halide ballasts, but hot re-striking of mercury lamps 100 watts or smaller on metal halide lamps may be hard on the mercury lamp since the starting pulse can force current through cold electrodes and the starting resistor inside the mercury lamp.

1,000 watt mercury lamps come in two operating voltages, one of which is OK for 1,000 watt metal halide ballasts. A few wattages of pulse-start sodium (150 watts?) come in two voltages.
A low voltage lamp in a high voltage ballast will be underpowered, resulting in reduced efficiency, possible reduced lamp life, and possible ballast overheating. A high voltage lamp in a low voltage ballast will usually cycle on and off, operate erratically, or possibly overheat. This will usually result in greatly reduced lamp life in any case.

One class of sodium lamps is made to work in mercury fixtures, but these only work properly with some mercury ballasts, namely:
'Reactor' (plain inductor) ballasts on 230 to 277 volt lines.
'High leakage reactance autotransformer' ballasts, preferably with an open circuit voltage around 230 to 277 volts. NOT 'lead', 'lead-peak' nor any metal halide ballast!

These sodium lamps may suffer poor power regulation and accelerated aging in the wrong mercury ballasts, especially after some normal aging changes their electrical characteristics. Also, these lamps may overheat and will probably have shortened life with pulse-start sodium ballasts.

Many sodium lamps require a high voltage starting pulse provided only by ballasts made to power such lamps.

To prevent dangerous accidents please keep remote ballasts away from tap points and on an elevated position (approx 5 inches off the floor) using a block or shelf.

 

A switchable ballast allows you to run a standard halide or sodium bulb from one ballast, you just insert the appropriate lamp and set the switch to the correct operating setting.

This type of ballast enables growers to bypass costly conversion lamps and maintain the higher light output from non conversion bulbs.

 

The color of a light source entails a complicated relationship of different factors, that are important in determining the right light source for your garden. The advantage of Metal Halide lamps is that they provide high-quality, crisp white light in a variety of different color temperatures that meet the needs of many different users.

Correlated Color Temperature(CCT)

The first factor in choosing a color of lamp is to determine whether you need a warm or cool light source. The CCT, expressed in Kelvin degrees, relates to actual thermal temperature. If you've ever seen a piece of metal being heated, you know that as the metal gets hotter, it's color changes. The CCT rating of HID and flourescent light sources indicate how warm or cool the light source is. For instance a lamp with a CCT of 2700 Kelvin is considered warm; with a CCT of 4200 Kelvin is considered neutral; and one of 6000 Kelvin is considered cool.


Spectral Energy Distribution

When you look at a light source, you perceive seeing a single color, but you are actually seeing thousands of hues. The combinations of different wavelengths of light make up the color we see. The relative intensity of the various wavelengths are used to determine a light source's Color Rendering Index(CRI).


Color Rendering Index(CRI)

The CRI is an indication of a lamps ability to show individual colors relative to a standard. This value is determined from a comparison of the lamp's spectral distribution compared to a black body at the same color temperature. Light sources, such as metal halide lamps, are rated with a CCT; however, CCT does not provide any information on the quality of the color. For this, a CRI is also necessary. In general, the higher the CRI rating of a lamp, the better the different colors will show.


5K - 7K Kelvin: Strong Blue Light
Promotes bushy growth. Ideal for rapid growth phase of plants.
Greatly enhances all-around plant growth when used with super
high output, high pressure sodium or 3K warm metal halide lamps.

4.2K - 4200 Kelvin: Cool white Flourescents
Can be used as supplimental blue lighting when used with a 3K
source.

4K - 4000 Kelvin: Neutral Metal Halide
Best single source for plant growth, producing shorter, bushier
growth than 3700 Kelvin and color rendition. Used in general
plant lighting.

3.7K - 3700 Kelvin: Softer Metal Halide(coated)
This coated lamp is used in general plant lighting and for more
rapid growth than 4000 Kelvin produces.

3K - 3200 Kelvin: Warm Metal Halide
Highest photosynthetically active radiation (PAR) value of all HID
lighting for all phases of plant growth. PAR watts account for the
nutritional value of light and are a direct measure of the light
energy available for photosythesis.

2.7K - 2700 Kelvin: High Pressure Sodium Lamps
Redder color mix, used for propagation, blooming, supplemental
greenhouse lighting.

 

HID (High Intensity Discharge) Lamps are:

* Efficient. They put out more light, with less energy usage, than any other type of illumination available to indoor growers.
* Bright. HID's produce more light than other types of indoor horticultural lighting.
* Expensive. HID's cost more than flourescents. They range in price from $50-$600 dollars.
* Hot. HID's produce considerably more heat than standard fluorescents.

Fluorescent lamps are:

* Inexpensive. Shoplight fixtures can be purchased for as little as $7. Compact fluorescent bulbs only cost a couple of dollars a piece.
* Locally Available. Most discount stores and home improvement stores carry inexpensive, fluorescent fixtures and bulbs.
* Fine for vegetative growth. Fluorescent bulbs put out plenty of light for plants growing vegetatively, including mothers, seedlings and clones. Some growers prefer fluorescents for vegetative growth because of the slower pace of growth and better root development.
* Fluorescents need to be in close proximity to achieve their rated output, which means their canopy penetration is more limited than HID's.
* Comparatively inefficient. 10 forty watt fluorescent bulbs use the same amount of energy as a 400 watt HID, but produce far less light. Since they use the same amount of energy but produce less light, the remaining must be given off as heat. Contrary to how it may first appear, fluoros actually run hotter than the equivalent wattage of HID-- they just disperse the heat over a wider area.

 

Mylar reflects about 94% of the light.
One of the best materials on the market for light proofing.

Mylar is a product that serves many purposes. The insulation industry developed this product to withstand severe temperatures. It acts as a moisture barrier as well as a reflector. The United States Navy uses Mylar aboard all of its Freight ships, Cruisers, and Destroyers.

Mylar comes in several different types:
White

Black

Metalized

Aluminized

Dimpled Metalized is available also.

Threaded Aluminized (reinforced)


What we OGer's are interested in is the obvious, we want to wrap our grow space, large or small, with the best reflective material available. Aluminized or Metalized Mylar.

Mylar is a chemical resistant, polyester film that is mostly tear resistant depending on mil. The reinforced Mylar is almost impossible to tear. It can withstand temperatures of up to 200 degrees Celsius, Mylar is also electrical resistant and fire retardant.

Unlike foil, mylar lays flat without the crinkles and creases if handled with care. Mylar WILL not create concentrated hot spots.

Material Gauges are as follows. 001", 002", 003", 004", 005", 007", 010", 014".

Most Hydroponic shops only carry 001" and 002" mil. Which is all you need if your using as a grow room reflector. Mylar can be cleaned with Windex, alcohol or any other mild household cleaner. I use an antibacterial hand soap with warm water.

 

Horizontally oriented lamps are more efficient for several reasons and should be seriously considered as the grower shops for a good light solution.

In a horizontal lamp arrangement, the arc tube that produces the output is oriented with its full length exposed to the reflective hood insert and plants. This provides excellent efficiency due to a proper direct and indirect lighting arrangement.

In contrast, a vertically placed lamp/arc tube has the poles (which don't provide any light) oriented such that they are facing the plants and the hood, bad deal.... calls for a parabolic type hood to deliver the light to the plants below. This is very inefficient due to losses incurred by the light first having to travel the distance to the inner surface of the parabolic reflector, and second, by relying on the reflective properties of the reflector's coating to distribute the light downward effectively which wont happen. There WILL be losses. Efficiency takes a big hit with vertically oriented lamps in parabolic reflectors.

Regarding horizontally oriented reflector efficiencies - the reflector should be small (for reasons already stated) and should be well designed with a gull wing insert which uses a quality baked-on white enamel designed to resist discoloration from the adverse affects of heat over time. A much better solution is to choose a corrosion resistant specular aluminium insert. The use of quality specular material is the way to go regarding getting the most from your investment.


When using bulbs above 600watts and growing plants taller than 1meter commercial professionals make use of broad side lighting. The lamps are positioned hanging straight down between the plants without a reflector.

PLEASE NOTE: When using any lamp in any orientation it is always important to prevent heat damage by ensuring there is ample spacing between the lamp and adjacent plant material.
Photo contributed by: Gypsy Nirvana

 

Mirrors waste energy by reflecting only a small fraction of the light that falls on them.


When light, which, like radio waves, is a form of electromagnetic radiation, strikes a metallic mirror the electrons in the metal move just as they do when a radio signal strikes an antenna. Pushing electrons around takes energy, which dims the reflected image.

Metallic mirrors reflect infrared light (heat) and if your mirror has imperfections this will cause hot spots, which can burn plants. Please note hot spots also apply to Mylar and Foil and IMO are not applicable to growers using small amounts of fluorescent lighting.


By using a mirror to reflect your light on a wall, you can test for imperfections, if you see an uneven image, with focused beams (normally located at the edge of the reflected pattern) these are known as hot spots and depending on the wattage of your bulb, may burn your foliage.
Metallic mirrors should not be used as a reflector for your grow room as minimizing light loss is important.