CFL vs. HPS in flowering - my conclusion

Discussion in 'Growing Marijuana Indoors' started by Vaporist, Jan 22, 2014.

  1. #1 Vaporist, Jan 22, 2014
    Last edited by a moderator: Jan 22, 2014
    After two different grows, one in soil and one in water, I am seeing the same problems with my plants that I believe are the result of using CFL lights - even though they are the correct color spectrum (2700k) for flowering.
    When the plants get a few weeks into flowering, the leaves show signs of nute deficiency (yellowing, brown spots, inordinant amount of dying leaves, weak bud growth, etc.) even when I have adequate nutes available and the correct PH. When I see my friend's plants who uses the same nutes, dosage, and room temperature, his plants don't have these problems. His plants also yield much better in less time.
    Here is the reason that I have concluded:
    I am using eight of the 55-watt CFL 2700K bulbs for flowering, and it is not evaporating enough water through the plant for it to be able to draw the water and nutes up into the plant.
    My friend who uses HPS has the same amount of plants (4) that I have. His plants go through two gallons of water a day. It takes my plants a week or longer to go through that much water! His house also reeks much stronger than mine does, and we are growing the same strains. I attribute that to his lights drawing more water through the plant and evaporating it into the house.
    Bottom line is, his single 400-watt HPS lamp is evaporating 10 times as much water through his plants than my eight 55-watt CFL lamps are. It goes without saying that along with that water, the nutes are going to be sucked up into the plant also.
    That points to inadequate lighting, right?
    A good comparison would be that he is lighting his plants with one sun and I am lighting my plants with eight moons.
    Any thoughts?

  2. dont believe the feedback cfls are not comparable to hps. cfls produce 69 lumens/watt or lpw hps produces 140-160 (400w=140 1000w=150 600w=160)
    hps also produces much more heat than cfl but nothing an exhaust fan cant handle
  3. Do you think it would be a good idea to switch over to HPS from CFL 30 days into flowering?
  4. HPS does zap the humidity out. That is in the point here right?
    I don't think I would consider it a bad idea at almost any point except just before harvest. More light is more energy, its like asking would you rather have $50 or $100?
    If its worth anything to you, with 1 plant under a 600W HPS I just harvested 105 grams. I don't think you could do that with 1 plant and 600W of CFL's
  6. Would a desiccant or dehumidifier replace the moisture draw in lieu of the extra heat? Warmer air holds more moisture than cooler air, so this sounds very plausible to me, but can that absorption be replaced by mechanical or chemical means?
    I'm interested in growing, and want to do it with CFL's or LEDs. And OP's results and ultimate conclusion is undeniable to me, fucking ingenious really.
    Interesting thought. A dehumidifier, like you said, would cause more transpiration. Moving air over the leaves though does the same thing. I feel like a fan blowing over the leaves would do the same thing for cheaper? Maybe somebody has done it before.
  8. #8 Bill O'Really, Jan 23, 2014
    Last edited by a moderator: Jan 23, 2014
    No. A fan just helps with evaporating the moisture naturally. A desiccant or dehumidifier EATS the moisture out of the air.
    Example.... If you put water on a floor in a sealed room then heat the air in that room the moisture will go into the air as vapor, cool the air and the moisture will appear wherever in the form of condensation. But a dehumidifier will mechanically remove the moisture and transfer it out of the sealed room without opening the sealed environment. A desiccant will absorb it without allowing it to be released back into the air at all....
    So a dehumidifier will actually pull more moisture out of the air regardless of heat, although heat will help it... A lot more air can be processed mechanically by that then just using an exhaust fan and This is good thinking by the OP. You too.... it made me think, since it's all about power consumption has the OP's conclusion shown that a, say hps lighting stem with a fan is more efficient than say a CFL lighting system with a dehumidifier.

    I would like to see a test grow that would use:
    Hps lighting and a fan.
    CFL lighting and a dehumidifier.
    And a closed system for both using a dessicant filter to draw in only dry air forcing the plant to absorb the water supplied by the grower.

    I'm drunk so I'm not sure if that makes sense to anyone but me. Sorry. Lol
  9. You seem to know more about it that I do. Luckily in Colorado I don't have to worry about the air ever being to humid. :yay:
  10. #10 Vaporist, Jan 23, 2014
    Last edited by a moderator: Jan 23, 2014
    I actually harvested an average of four ounces per plant on my last soil grow with these same CFL's - but the plants were six foot tall. I started getting yellow spots and what looked like nute deficiency a few weeks into flowering. The same thing has happened in hydro at about the same time. I figured it had to be the low-intensity lights.
    Like I said earlier, it seems like I am trying to grow a plant with eight moons instead of one sun for lighting.
  11. I don't know shit... I'm still learning. Forgot about CO air being dry. I'm hoping to move there later this year from Delaware. Me and my wife need a change of pace. Had an opportunity several years back to go...a friend moved out there, told me "you can move to Colorado, or you can move to New Jersey... but if you stay here you won't have to move to New Jersey because it is moving here". He was right, I wanted to, she wouldn't listen... now every where you turn the moons think they're mafia and Jersey shore.. Fucking sick what they've done to our politics. We were the first state to ratify the Constitution, in defiance to the King, now they don't even have the balls to tell Eric Holder to piss off. Fucking neutered bunch of pathetic wankers. Not even sure if they are real Americans.
  12. But is it the amount of photons, or the amount of moisture being pulled through the plants system? Like dialysis for plants? How much light is enough... And is it just the light passing over the plant, or water/food being forced/coerced through it? I'm pulling up a chair and tuning into this...
  13. I just ordered a 400-watt HPS lamp and it should be here on Monday. I'll post the results after a week.
  14. are you sure they're not 55-watt equivalents versus 55 actual watts?
  15. #16 Sammyy, Jan 23, 2014
    Last edited by a moderator: Jan 23, 2014
    His plants go through water quickly because an hps is more heat and is also going to grow bigger plants which in turn, need more water, and if there in smaller pots that just adds to itHis stinking more most likely has to do with strain more than anythin but hps is going to help with bud production better than cfl would which = more bud and more bud = more stank
  16. yeah OP are you and your friends plants of the same genetics? and do you both use the same methods and nutrients to grow with? lot of variables here
  17. #18 Guest55445566, Jan 23, 2014
    Last edited: Jan 23, 2014
    CFLs for flowering?  Any serious grower will laugh at this prospect.  Your CFLs are producing like 3000 lumens of mixed red and blue light (depending on the spectrum).  One 600w HPS light produces 92000 lumens of pure red.  That means your plant is getting roughly 30x the light.
  18. #19 Guest55445566, Jan 23, 2014
    Last edited: Jan 23, 2014
  19. Also to take into account is the light penetration difference between the two types of lights. Light from CFLs has very little light penetration compared with an HID light. When you perform this wonderful experiment, it would be most efficient to position the CFLs very carefully around the plant to enhance the amount of light that actually gets used by the plant.
    Best of luck Kapt.

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