24/0 or 18/6?

frmrboi

Well-Known Member
im sorta gonna high jack this thread for ONE question.. but i heard it isnt good to run HID's for 24 straight.. (i veg/flower under t5s due to the space i was using.. just ungraded to a bigger room)... anyways.. is that true??
just the opposite, the start up erodes the bulb's electrodes each time, leaving it on constantly extends the life of the bulb and probably the starter too.
 

simpsonsampson420

Well-Known Member
sweet.. i read the complete opposite but it makes more sense what you said... i wasnt sure how letting the light bulb "rest" would make it last longer.. lol
 

Dfunk

Well-Known Member
Letting the light rest will make the bulb maintain it's lumen output longer, but as the above poster stated the wear & tear of turning on & off will shorten overall life span. I've read that plants grown under 24/0 schedule produce more males. I will have to run a future experiment to test this theory. I currently use a 24 hour cycle, but I'm considering switcing to 20/4 schedule to see how that works. I believe a little darkness is probably good for balance. I also use a combo of CFLs, tube floros, & a 400W HPS & i had this idea that maybe I should give them full light for 16 hours & then only partial light for the rest. In nature Cannabis does not recieve 16 hours of direct light. I think that 10 to 12 hours of direct light is sufficient. Any feeback would be great.
 

frmrboi

Well-Known Member
Just want to add that I flower with my lights on 24/7. I'm a small grower so I just swap out half my plants into a light tight closet for 12 hours then change every 12 hours. Twice the output from the same space.
Lights are electric appliance, they don't need to rest or get some sleep so that they'll be refreshed in the morning.
 

Dfunk

Well-Known Member
I wasn't saying the light NEEDS rest...I was just stating that the lumen output would remain higher for longer if they use the light less. It sounds like you & I have similar growing techniques. I use a balcony & CFLs in a room to vegatate in two spaces & then flower in a closet. Great minds think alike?
 

the420 apprentice

Well-Known Member
ok think were of the lighting schedule subject but i dont care what anyone says 18-6 or 20-4 give me the best grow and there is no difference in the of stretching. i think stretching is half light and half genetics.
 

K1Ng5p4d3

Junior Creatologist
My last grow i had 5 plants under 24/0 for veg under a 600w MH, then switched to 12/12 HPS for flower. they grew out to be about 4' tall, with nice node spacing, and 2ft long buds. This time around i have 10 plants under 1000w Mh 18/6 lighting, and i just switched them over to flower last week. Theyre still under 2ft tall right now, but im hoping that theyll get a little more stretch to them personally. The node spacing is SUPER tight right now, and even though thats gonna make for some really nice big rock hard nugs, the spacing will do the plant some good as far as light penetration goes, and will improve my overall yield, as theres not enough light getting to the undergrowth on some of the plants. Im trying 24/0 vegging on my flood tables, where i have 28 plants going right now. theyre about 2 wks old under 1000w MH, and just getting their footing in the hydro setup, but ill come back and let you know what the difference is. (i have a total of 2600 available watts of lighting, but right now im only using 2000. Once i set my growroom up like its supposed to be, ill be using the two 1000w lights over 4 tables, with a mother tent set up under 600w, and a clone chamber with various CFLs powering that shit. all in due time...)
 

CarJobWeed

Member
thank you everyone for helping me with this delima... maybe in conclusion 24/0= closer node space 18/6= longer node space( taller plants ) ... im using a 400w hps all the way through and ive kept it on 24/0 for 21 days now...thanks all.
 

Gaines04

Well-Known Member
I don't think the "savings" from of 18/6 is worth the time lost waiting for the plants to get ready to flower....
I run my 400mh constantly in my veg room... its like Denny's - we never close.

24/0 GETS MY PLANTS READY FOR FLOWER FASTER WITH SHORTER NODE DISTANCE
MY BITCHES WORK ALL DAY & ALL NIGHT BUILDING FRAMES FOR HEAVY FLOWERS

They can rest when they get into 12/12...

this philosophy was taught to me by my mentor, who's been commercially growing for 20+ years in NorCal

don't be scurred to work your bitches... you'll be surprised....
LOL@ like Denny's we never close.. funny shit. NO DOUBT GreySkull.. those bitches can rest producing big buds in flower...:hump::joint:
 

DirtyCanuck

Active Member
Would males not be already determined once the seeds sprout? I think perhaps one could find a correlation to hermies but I still have yet to see it. Everytime this arguement comes up I hear a lot of people saying that in nature the sun isn't on 24/7 and that we should mimick nature. However the thing that I think a lot of growers are set out to do is go far and beyond anything nature could reasonably offer plants. We do this with nutrients, lighting, cloning, topping and with hydroponics and aeroponics.

Lights on 24/0 is another thing on the long list of nature screwery.
 

K1Ng5p4d3

Junior Creatologist
Sex is absolutely determined for a plant once it has popped from the seed. Once that plant gets goin, there is nothing you can do to stop a plant from being male. As far as hermies go, i dont know - as in, if your growing bagseed, and your plant is going to end up being a hermie, is there anything that can be done to prevent those male flowers from popping out with the pistils when sex starts to show? I wish i had a clue in that department man, lol. I dont think there is though. If a plant is predisposed to be a hermie, i think that were fucked, but as always, theres a plethera of things we can do to ensure that our female plants dont go hermie on us. Theres even things we can do to our seeds to increase the chances of getting female plants from them. But once they pop, you pretty much just get what ya get, lol. If your not a breeder, or trying to produce seeds, Buy Feminized :D!!!
 

Nocturn3

Well-Known Member
thank you everyone for helping me with this delima... maybe in conclusion 24/0= closer node space 18/6= longer node space( taller plants ) ... im using a 400w hps all the way through and ive kept it on 24/0 for 21 days now...thanks all.
I have heard that 20/4 is the optimum veg timing schedule, with regards to end yield. Here is post written by OT1 on the subject:

Originally Posted by oldtimer1

We did a lot of experiments with light times a few years back using known sat and sat dom clone lines.

With Vegging ie under hid lights.

20/4 produced the most sturdy growth and the most bulk. Best final yield, taken as 100%.
22/2 Less of both. yield 88%
18/6 Studier than 22/2 but slightly less bulk. yield 87%
24/0 Much lighter in all aspects than 18/6. Yield 79%
16/8 The weediest plants. yield 67%


For the mum lines we have 20/4 to 12/12 gives the best crop weight and bud quality, really thats all I’m interested in.
Taken from here.
 

MrJoshC

Well-Known Member
I agree, there are certain organisms that can effect sex after it's been determined. Crocodiles are an example of this, a warm nest means for males, a cold one more females(I might have got that backwards). I haven't seen any quality studies in reference to MJ, but I absolutely think it could happen. This may surprise you, but there is actually studies done with this about humans. The results are only marginal, but "typically" a stronger female will produce more males since the testosterone does more damage to the mother then a female child would. And a stronger mother can sustain that damage better.
 

tilemaster

Well-Known Member
i just ran 24/0 throughout veg w/ 2 hid's =1k. i saw crazy growth but temps are much easier for me to control on 18/6 or better yet 12 12. for me with 2 HID's its more of a seasonal desision, its cold here 8 months out of the year, still snowing, so i can run 24/0 in the winter months, but i think id be hitting high 90's in august going that route. when lights go out it automatically drops in there to 65 an optimal night temp.
 

johnnyseed412

Active Member
24/0 makes less stretch and also faster root structure.

18/6 more stretch and less root structure. More LESS likely to become rootboun
 

plaguedog

Active Member
24/0 makes less stretch and also faster root structure.

18/6 more stretch and less root structure. More LESS likely to become rootboun
The better the root system, the better the final yield.


Aloooooong time ago on overgrow there was quite a few side by side grows using 24/0, 20/4 and 18/6. The consensus was 20/4 delivered the best results. Your plants need a rest. Since those times I have used 20/4 for years. Seems to be about the sweet spot.
 

crispypb840

Active Member
Plants grow better and healthier with a night cycle. MJ releases co2 at night and consume co2 during the day. This is a natural part of the growth process. This has been a controversial topic for a while now and you will always get people who don't really know anything about how the plant actually grows telling how it is.. Its all physics. Also environmental triggers along with genetics. The length of the night cycle can have an impact on a lot of strains differently. Most identifiable is in the height of the plant. Every strain reacts differently. Yes they can grow ok on 24/0 but not faster. Maybe a rudy (ruderalis) will grow better under 24 b/c it is in it's genetics to vegg and flower under longer days and shorter seasons. But if there is sativa in the Geno then this is not the case since the days are much shorter and the seasons are longer. Get it? Makes sense huh?...
right ! and believe it or not your lights will last longer (hours wise) so the extra electrical cost is offset by the extended life of the lights.
Plants don't get "tired" and need to sleep.
 
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