24/0 vs. 18/6 debate is over!!!!

Discussion in 'General Marijuana Growing' started by mafuki, Jan 15, 2010.


    Chickenchoker New Member

    zombies are cool

    bigsteve Well-Known Member

    Mafuki -- congrats on today being your fifth anniversary here at RIU! From one OG to another, keep up the good work!

    mr sunshine

    mr sunshine Well-Known Member

    The benefits don't outweigh the energy used in my case...those extra 6 hours don't do enough for me to spend money on them... plus your equipment will feel the extra work bulbs, ac...your gunna have to water more frequently. .. The real question is does the positive outweigh the negative! In some situations it might.. In others it might not!
    Last edited: Dec 17, 2014
    a senile fungus likes this.
    a senile fungus

    a senile fungus Well-Known Member

    You're so sexy when you talk like that...

    Do it again, I wanna watch you...

    RM3 Well-Known Member

    I'm usin it also and lovin it, I didn't care bout electricity use, I switched cause I'm bout to grow some land race Sativas and heard it helps to control em. I just flipped my first ones into flower and after 1 and 1/2 weeks from flip they are budding with a 3 inch stretch LOL and over twice as many bud sites. IMO Gaslight Veg is da shitz
    kushlatte and ttystikk like this.

    bengi Well-Known Member

    I usually do 20/4. Figured the debate is 24 vs 18/6. I will meet in the middle.

    ttystikk Well-Known Member

    I've done six on and six off twice a day, and the plants don't like it very much.

    18/6 seems to be what the ladies like best around here, 24/0 didn't give significantly better growth.

    TheChemist77 Well-Known Member

    until somone does a true side by side comparison the debate will continue. even then some will opt for one or the other depending on what they like their plants to do, short nodes or stretch...i use 24/0 for clones and begining veg, then switch to 18/6 for a week before flipping to 12/12.. only seed moms go directly under 18/6 till they are mature, as i get more females under 18/6 than 24/0,, dont know why but its true..
    BxHaZe87 likes this.

    althor Well-Known Member

    Well, let me just put in realness without a bunch of numbers...

    Put a clone in 24/0, one in 20/4, and one in 18/6...
    When you yield months later this is the order you will find, over and over and over...
    20/4 has the best results.
    18/6 has the 2nd best results.
    24/0 just fucking sucks. So yeah.
    DesertGrow89 and GroErr like this.

    GroErr Well-Known Member

    I've tried them all and did similar tests with same strain clones. Whether it's better or not to give them some rest, what I found in my setup and observations was that 20/4 was a good in between option and found less early (1st 4 weeks) defs show up when I run them at 20/4 so I stick with that now whether seeds or clones. That said, I'll still use 18/6 and even 16/8 from time to time like in the summer to manage heat or slow them down at 16/8 when waiting for the flower room. They all work, use what works for you.

    RM3 Well-Known Member

    What no one seems to have done in their test is to see the relationship with the stretch? The more light in veg, the more they stretch, longer they take to start budding. The more dark they get in veg the less they stretch and they start budding faster, they also make more bud sites. I use the Gaslight Veg or 12/1 and I just flipped one last sunday that is already budding with 24 bud sites in the top 8 inches, before I switched to Gaslight, I did 16/8 :)

    edit/add, it only stretched 3 inches :)

    Last edited: Dec 18, 2014
    DrDank likes this.

    ISK Well-Known Member

    funny, on my recent experiment I had quite the opposite, the 16/8 room stretched way more than the 20/4 room, but there was other factors to consider

    TheChemist77 Well-Known Member

    i was under the impresion u get more stretch in 18/6 than 24/0,,,i put my plants in flower after only 2 weeks from rooted clone, in flower they triple in height, thats w/ 24/0 in veg.. are u saying if i veg under 18/6 ill get less stretch in flower?? what would u recomend when my plants only get a 2-3 week veg time?? as soon as they root, i top, then give them 1-2 weeks to recover then flip to 12/12
    Dr. Who

    Dr. Who Well-Known Member

    The stretch has been taught/explained like this.

    The plant is reacting to light spectrum changes. More accurately "The duration of far red nm band exposure".

    (The following is paraphrased from memory)

    As the plant gets increasing red (R) and far red (FR) nm band exposure (in the "fall") as the light spectrum increases in that wave length. The plant reacts by "reaching" for the more blue spectrum to continue growth as the red & far red has more penetration into the canopy and causes hormonal changes in the plant to begin flowering.

    (I forget which textbook that came from, so I can't give credit here.)

    Thus it has been found that if you run MH all through out the grow. You will get less stretch. Your bud structure "appears" more full because the shorter budding internodes, tend to have the buds "come together" to form a more "massive" bud on the mains and branch ends.

    The last statement is true in varying degrees to all strains.


    Edited to read " more" from "less" at 12:05 after UB had pointed out by backwards mistake.
    Thanks again UB!
    Last edited: Dec 19, 2014

    RM3 Well-Known Member

    They build up flower hormones in the dark, the more dark the more hormones, the more hormones the less stretch. To be fair I do have more blue than red in my light setup which also helps with this. as for recommending stuff, well the more you veg, the more you yield
    BxHaZe87 likes this.
    Uncle Ben

    Uncle Ben Well-Known Member

    Dark means growth, especially if not only get good culture but have a decent drop in day high temps to night low temps.
    Cpappa27 and GroErr like this.
    Uncle Ben

    Uncle Ben Well-Known Member

    In reality it's the R and FR that do penetrate into the canopy, thru leaves.
    Dr. Who, Cpappa27 and GroErr like this.
    Dr. Who

    Dr. Who Well-Known Member

    @Uncle Ben
    Ya know UB,,,I went back and changed (edited after replying) it to the present form because I couldn't remember if I had it the right way. Damn getting old anyway ("RAGE,,,RAGE, at the dying of the light!").

    Thanks for the correction!
    Uncle Ben likes this.

    TheChemist77 Well-Known Member

    i know the blue creates a closer node space so a more compact plant, but as for the 24/0 or 18/6 under my mh in veg which is better,,causes less stretch?? my flower room is hps so my plants do most stretch in flower.. i have flowered under a mh before but i thought the yields were not as good as flowered under hps,, but they were very nice compact tops under the mh..

    TheChemist77 Well-Known Member

    as of now i have, a 400 watt mh for my veg, a 150 watt cfl for clones and 2 600 watt hps in flower.. do you guys think it would help to have a 600 watt mh and a 600 watt hps in my flowering room?? i have digital,mh,hps ballast's and both hps and mh bulbs so i could do which ever would get bigger yields..i also have 4 4ft T5 fixtures with 6500k bulbs so i could run both 600 watt hps and put 2 T5 bulbs to each side of the hps cool tubes just to add a little blue also... which would be best?? its a 4 foot x 6 foot home made dwc or nft set up..

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