General Lighting, Ventilation, Watering, Nutes INFO

[Darkhaz3]

Hey everyone, i've noticed ALOT of people asking basically the same questions recently and thought maybe this would help:

Lighting
HID(High Intensity Discharge) - HPS and MH lighting
HPS(High Pressure Sodium) - mainly used for flowering stage - Red Spectrum(2700K)
MH(Metal Halide) - mainly used for veg stage - Blue Spectrum(6500K)

Although both types of light can be used throughout both stages together for a full spectrum, thus a larger and more potent yield.

For all HID lighting, a ballast is required. almost all ballasts u buy for HPS lighting will also fit MH conversion bulbs.

Light Coverage
150 watt - 1'x1'
250 watt - 2'x2'
400 watt - 3'x3'
600 watt - 4'x4'
1000 watt - 5'x5'

To maximize light efficiency use a reflector for your light and cover the walls of your grow space in mylar or white paint.

Position your light(s) as close to the tops of your plants as possible without hurting them (usually 12 to 30 inches depending on wattage of light and cooling techniques)

Ventilation
General rule - heat rises so cut ur exhaust at the top, intake at the bottom.

CFM - cubic feet per minute

When looking for an exhaust fan, consider u want the air of your room cycled 2 or 3 times a minute. So a space that is 4'x2.5'x5'=50 cubic ft.
Therefore look into a fan that is around 150 cfm.

For intake, you can simply start by cutting holes towards the bottom of your box/space for a passive intake, where air is automatically sucked in as air is sucked out by your exhaust fan. If it is too hot in your space add an intake fan with same/less cfm than your exhaust fan.

Another simple way to solve a heat issue is with fans blowing on the light, and blowing across the space between the light and the plants.

Watering
There is no direct answer to the question "how often do i water?"
Everyones setup is different - temps, humidity, soil, nutes/ferts.

An easy way to check if u need to water is to stick your finger into the soil about an inch or two deep and if it feels dry, give it some water. Another way to tell if u need to water is if your leaves start drooping. be careful because this can also happen if overwatered so check the soil also.
Remember it is better to slightly underwater your plants to build stronger roots.

When watering, you want about 10% of what you pour in to come out the bottom through the drainage holes.

ph - desirable ph for soil grows is 6.0 - 6.5
some soils like FFOF come ph adjusted already

It is always better to use filtered water to ensure no chemicals that would through off ph.
However, if using tap water, let it sit out in containers for 72 hours to evaporate chlorine and other chemicals.

if u have a ph meter u should check the tap water and the runoff from the plants after u water just to be sure.

Nutes
Do NOT give to ur plants for first 3 weeks of growth. Superthrive in very small doses is ok.

NPK Rating - Percentages of Nitrogen, Phosphorus, and Sodium (0,0,0)
Veg - more nitrogen is desired ~(8,4,5)
Flowering - more phosphous id desired ~(5,8,4)

Start at 1/4th strength and progress to full strength at each stage.

Stop using and flush water through your plant a week before harvest.


I hope this maybe answers a few questions for some people. I know alot of people know this stuff already, but i thought i'd make life easier by putting it all in one place.

Let me know if you have questions

[LoganDLX]

pretty helpful info.

[Anony]

Not bad at all + rep for the help to noobs. Are you planning on updating/categorizing it? If so can I use it for my sticky?

[Merfolk]

nice info

[Darkhaz3]

Originally Posted by Anony

Not bad at all + rep for the help to noobs. Are you planning on updating/categorizing it? If so can I use it for my sticky?

Thanks man, yea u can put it in your sticky.

[Substang]

glad i found this

+rep

[Anony]

I am going to add this to my sticky today, so if you ever come across more info you want to add to it, please do.

[jzchillin]

nice, you should check out my lighting thread. and your welcome to post anything i haven't covered yet.

[Darkhaz3]

thanks guys, nice lighting thread jzchillin

[Substang]

hey im following your ventilation info and i gotta question. im makin a box to grow and the dimentions are about 5 ft by 3 ft by 3 ft so the cfm should be about 150 cfm?

[Darkhaz3]

exactly
5x3x3=45 sq ft x 3 times a minute = ~150cfm