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Ratio of Red to blue spectrum during flower

Discussion in 'CFL / Fluorescent Lighting' started by jr22hockey, May 5, 2010.


    jr22hockey Well-Known Member

    I was thinking for every 2 watts of Red, you should have 1 watt of blue.

    What do you guys think the best ratio is?

    fredsgrow Active Member

    I'm running 1 "cool" (6500˚K) bulb for every 3 "warm" (2700˚K) ones. My girl seems to be enjoying it:D It also seems to be a popular configuration on these forums. I'd say that you should be fine as long as you've got the majority of your light in the spectrum that would most benefit your plants at that particular stage in their lives! I've also read that at least 100 watts/plant for averaged-sized CFL grows is needed to ensure vigorous growth and 4 23w CFLs/plant helps to achieve the 3:1 ratio easily. 23 watt CFLs also tend to be the most efficient/practical CFLs as far as lumens/watt go. I hope some of this helps (I'm a little stoned, hahaha!)

    jr22hockey Well-Known Member

    Yeah man that did help. Thanks.
    Here's another question that I think I know the answer to. haha

    You have a blue spectrum bulb laying around that you're not using and your plants flowering.
    To add or not too add?

    Answers to add right?

    fredsgrow Active Member

    It wouldn't hurt. As long as you're running the right light schedule your plants will flower. Keep in mind that the light spectrum will determine what type of buds you harvest. Generally, red light will give you denser buds, blue will give you fluffier ones, though I hear plants flowered under more blue light tend to produce a "clearer" high. I'm only flowering my first crop right now so I can't give you any hard evidence yet, haha!

    doctor.j Well-Known Member

    what do you mean by clearer high
    ss your outta here

    ss your outta here New Member

    mixed spectrum is the way to go :)

    kingdavid918 Well-Known Member

    im using 4 26 watt 2700k and 2 23 watt 6500k and my girl is flowering her ass off!!!!

    fredsgrow Active Member

    Here's an article. Apparently the quality of the bud will be better because blue spectrum bulbs like MH emit more UVB light than red-spectrum HPS. I thought it had something to do with the type of high like harvesting based on the colour of the trichomes, guess I was a little off. Wonder how that could have happened . . .bongsmilie

    doctor.j Well-Known Member

    huh, interesting, you learn something every day, thanks fred for clearing up what a clearer high means:-P

    daisydobey Active Member

    hey so if i have a 600w hps horilux bulb

    and then i add 2 24w blue spectrum cfl lights on the sides

    will this increase potency of bud?

    trifase Active Member

    I have four 25W and one 30W WARM,
    and only one 25W COLD/BLUE

    so I use mixed, but on very low ratio: I noticed buds don't fatten up under blue as they do under red
    just my two cents :)

    Murfy Well-Known Member

    i use 2 1000w 2700k hps, and 3 400w 7200k mh for flower, and it seems to work pretty well

    marti221 Active Member

    No. It will add a variation in the spectrum of light. which in my opinion, and many others, this is what you want in all stages of cannabis growth. This is what the plants recieve in nature (Full spectrum sunlight). Doesn't it make sence to imitate this light the best we can? I think so. Cannabis uses both red and blue spectrum light throughout ALL stages of growth.

    As for the UVB light goes, this WILL increase resin and therefore, potency! The resin of cannabis protects from UVB rays. When UVB is added, more resin is released for protection. Its that simple. You can add UVB with MH lights, (they give off a good amnt of UVB light) and the cfls sold at pet stores for reptiles (If you look at the package many of these lights give out UVB).

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