lighting for autos? blue or red lights

Discussion in 'First Time Marijuana Growers' started by gariss, Nov 19, 2014.

  1. hey so im planning on growing 2 auto plants and a fail safe fem. plant incase one dies (will only have for a week or two after germ.) in a small enclosed box like area. I want to use cfl lights and was guessing that i need at least 200 watts(100 wat per plant). Is that right>? or what do you recommend for two plants? Also i was wondering if i should use blue, black or red lights combined with regular sunlight cfls? 
    Any help would be great 

  2. THanks! I was just wondering, ive read that you shouldn't mess with an autos light schedule, so would it hurt the plant switching from a blue cfl to a red ? 
  3. or would black/yellow lights work better?
  4. #6 Indie-Kah, Nov 19, 2014
    Last edited by a moderator: Nov 19, 2014
    OK...first, not precise, but well said by my hydro store's owner:
    "Want to know how good a CFL is for growing? Drop it on the sidewalk from 10 feet. It's just as good after, as it was before"

    That spectrum for veg, red for flower. You can flower under blue, but vegging under red slows plant growth.

    Reason's wavelengths are shorter, therefor higher energy. During flower, you reduce time under light partially to reduce how much light energy it gets for creating sugars from water and nutrients. That's also why you switch to red...lower energy, therefor it goes to producing blooms, not sugars.

    Next...WHY CFLs suck...a bit of a science lesson here.

    Light falls off at a square of the distance from the source. 1600 lumens (100 watt incandescent equivalency--typical CFL) at point measured for rating (glass of the bulb) falls off at a square of the proportionate distance you move away from the at 18 inches, it's 1/324th as strong...or 4.9 lumens.
    Nature averages 128,000 lux (lumens of direct light per square meter) of sunlight at sea level.
    While the tested lumen output of a 400 watt HID is 32,000 lumens...or 98.76 lux at 18 inches.

    Figure that out...your CFL is the equivalent of a 100 watt incandescent, and delivers a mere 4.9 lumens at 18 inches...that is what it delivers in DIRECT light...reflected light is weaker. A 400 watt equivalency delivers a mere 19.6 lumens. A "true wattage" comparison (23 watt CFL...get 400 watts of them requires 17-18, you'll be a hair above or below...we'll go with 18) still delivers only 88.2 lumens, the same heat, the same power consumption ( truth, more heat and power consumption, because CFLs are less efficient in true wattage than HIDs, even with their ballasts).

    So you tell me...would you rather pay under $200 for an HID system, or buy bulbs and fixtures for 18 CFLs that still won't match the light intensity, with worse draw?

    People who give you the "100 watts per plant" rule of thumb are wrong. They're working from quotes on the fact the SUN delivers about 120 watts per square meter at sea level. But watts are NOT light, watts are "power to do work". Watts are defined as 1 joule per second, a joule is the unit to measure energy expended in "doing work", whether that is heating, creating light, or making something move. That "120 watts" is what energy is STILL THERE to do work...the "watts" that became light were spent LONG ago...8.3 minutes ago, to be precise.

    Your lights give off not just light, but heat. Every joule of heat given off is a joule that doesn't become light.

    LIGHT energy is measured in lumens or lux (lux being 1 lumen direct light per square meter).

    See an inconsistency, there? "120 watts per square meter" from sunlight, but "128,000 lux". Sunlight's a lot more efficient...more light, less heat, in proportion.

    And it's "natural conditions" you want to mimic to the best of your ability, for a happy plant.

    Clearly, with the limitations of manufactured light, you won't be delivering 128,000 lumens 6 feet from the bulb without instantly burning down the neighborhood. You won't get a tenth of that without torching your house.

    And wattage has ZERO to do with lumens produced, except in comparison to another bulb of the same type. Wattage is determined by Ohm's Law. What's the volatge of the circuit? What's the current going through it? Watts equals volts times current. If your item is on a 110V circuit, and the circuit draws 1 amp, due to inefficiencies of AC power, it's a 100 watt item. Period. That simple. Resistance is voltage divided by current. Your 100 watt rated item has a total resistance of 100 ohms. That resistance is the resistance to doing SOME sort of work. In the case of a light bulb, it's creating light and heat.

    So a 23 watt CFL that puts out the equivalent lumens of a 100 watt incandescent is simply slightly over 4 times as efficient at turning electricity into light instead of heat. While a 400 watt HID is TWENTY times as efficient (and a 1000 watt HID is FIFTY times as efficient).

    LEDs are also more efficient...more efficient even than HIDs. Problem is that a 3 watt diode is less efficient than a 1 watt, and a 5 watt is even less efficient...1 3 watt LED puts out equivalent lumens as 2.75 1 watts, a 5 watt the equivalent of 4 1 watts.
    But LEDs aren't concentrated in one tight can't pack 1000 1 watt LEDs into the space of the surface of a 1000 watt MH bulb. Just can't be done.
    And each individual "bulb" gives off lower lumens---higher for the wattage rating, but lower in number. So there goes that fall-off problem again (which is why LEDs have penetration issues...40 5 watt LEDs have the same total light output as 200 1 watt ones, which, collectively, put out more than 4 times what a 250 watt incandescent produces, with FAR less heat...but each one puts off far the fall-off factor is far more significant).

    CFLs also lack in quite a few of the bandwidths plants need...the UV and IR releases are too little for what the plants want/need, for instance. For another example, our sun is primarily yellow-orange in spectrums of visible light. The plant disposes of green wavelengths by reflecting them...but if your plant looks almost like it does if it were outside on a sunny day, this means your light carries a HEAVY load of green, yellow, and orange...and the plant will only use the low end of that orange spectrum, as it approaches red.

    HIDs have the same issue in the visible spectrum, but are better about the UV/IR (still not enough UV).

    LEDs have the fall-off issue, and also huge "gaps" in bandwidth. The LEDs may be "targeted light", but ALL the plants get are those itty bitty narrow bandwidths the LED emits. So the more channels, the better, so you actually cover all through the red and blue areas, not just "4.2 nm wavelength" and "8.6 nm wavelength", when a healthy plant uses the 3.6 through 4.8 nanometer wavelengths of blue, and the 7.6 through 8.8 nanometer spread of red, in visible light, as its primary bands of use.

    In short..CFLs can be used...but don't expect them to do anything worth a shit, and no matter WHAT you do, know that NO single type covers all the bases.

    IMO, a smart person builds their own hybrid system to match their needs, abilities, and conditions, matching their opinions of what works best, or experiences.

    And always remember...asking questions here, all you get are people telling you THEIR opinion or experience, when they tell you "how you should do something". None of us have exactly the same conditions to work with, the same problems, restrictions, experiences.

    Yeah, you should pay attention when someone can tell you the "why" of something in a way supported by figures and indisputable facts, but someone telling you something backed by figures and confirm-able non-anecdotal facts is not going to be telling you "how you should do it", only what those facts ARE, and MAYBE their opinion on what to do with/about them.  Meaning "the sun emits primarily in the yellow-orange spectrum in visible light" is a fact that can be confirmed, 80 different ways, including stepping outside with a light spectrometer, or looking up what scientists have reported by testing that way, but "I did that that way, and my plant died" is anecdote...they could be wrong on the "why" of the plant's death, or their conditions may have been such that it killed their plant, while in YOUR conditions, it would make it thrive.

    And that last includes my OPINION about the uselessness of attention to what I said about WHY I hold that opinion, as THAT is indisputable and factual. THAT I think that about them is purely opinion, though based on those facts, and should be taken as just that...the opinion of a mouthy asshole. It only matters one way or another what the opinion is if the stone facts support it...and even then, YOUR opinion as to whether that's a concern are every bit as valid as mine that it's cause to see them as literally useless.
  5.  respects 

    thanks so much for the advise !!!
  6. The bottom four paragraphs are the real advice.

    The rest is just "why" explanations of goals <grin>

    No two people grow in exactly the same conditions. We all have the same desire to deliver the best we can to our plants, but you'll have problems I don't, and limitations or advantages I don't.

    So you have to do your best to handle the problems you face while doing your best to maximize the advantages or overcome shortcomings that none of us will EVER fully overcome.

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