18 or 24 hours of light

Dr. D · Nov 15, 2004

Which is best fot u guys i always use 24 hours light for veg, but i recently read some where that some plants afghanis or pure indicas grow faster under 18 and i had my shit (indica) under 18 for a short while then they went to 24 and im sure the growth slowed in 24...any feed back on how you guys ( and gals) do it wud be a great help as we all want the fastest growth ..

Joemutt1978 · Nov 15, 2004

I would say 18,

I always give my veggers a little dark, not on a timer or anything, usually just cut off the lights on my lunch break, and cut them back on when I get home, that is the hottest part of the day so the lights are off.

I think that something happens when they are in the dark, hormones or something, but it is good, they need dark I think. On younger ones you can see yellow leaves right when you cut on the lights, these are all new growth. It happens alot quicker in the dark, I have found.

Good Luck.

The Hashasin · Nov 15, 2004

18 or 24?

18 or 24?

Hiya Doc,
I'm now a converted 18/6 man. I used to use 24 hr HPS with 5% blue. I have upped my lumens since from 250 for 400W and going 650 for flower. I am convinced since growing the same species for 4th time that the 18/6 is the best. There seems to be more spurt of growth over night and the plants color has remained a healthy green, not the dark green I was experiencing with 24hr regime in veg. Hope that helps some, they definalty need time to photo synth... :canabis:

Guest · Nov 15, 2004

High Dr D. I have read that a plant can only process 16-18 hrs of light per day efficiently. After that, a point of diminishing returns is reached and the electricity is used inefficiently. I got that from Jorge Cervantes book "Indoor Marijuana Horticulture". Hope this helps. peace

ezozo · Nov 15, 2004

I am using 24/0 with out any problem (400MH) but I think I will try 20/4 or 18/6.
It will be nice to hear some experienced grower.

Thank's Hashasin for you imoput..
peace
zozo

badmf · Nov 16, 2004

With this you have a choice, 24 will grow faster than 18/6 as the plant "light" activities utilise photosynthesis at a higher rate than including a dark cycle. But there are advantages to having a "nite", as root development is increased and plant "light" cycles are set, otherwise the plant sees only one long azz day instead of many, which if from seed will cut back its maturity. Most plants need at least 2-3 months to fulfill their potential so to do anything that would shorten this will cut from its potency and yeild development. Answer is go 24 for a couple days then 18/6 from seed and clone after 2-3 months minimum. Without going into scientific detail, the processes the plant goes through while dark are beneficial.

Californian · Nov 16, 2004

not 24

not 24

Use 18/6. Photosynthesis involves both light and dark cycles, look up the "Krebs cycle" if you really want to read more.

dowink · Nov 16, 2004

I always start out at 20 hrs until the leaves with 5 sets start forming. Then switch to 24 hrs. This seems to always give me more females.

So Quick · Nov 16, 2004

I don't think 24/0 justifies the extra electricity and wear and tear on your ballast...I've never done a side by side of the 2, but I have vegged in both...and I prefer to go 18/6...

SQ

herouana · Nov 16, 2004

good question and answers now i don't have to ask.

Dr. D · Nov 16, 2004

awesome response

awesome response

Thanks for ur input evryone im gonna go 18/6 now .thanks

Harry Gypsna · Nov 16, 2004

use 18/6 if ur timers r reliable, its better to give em some "down time" to use the food theyve taken in if u get me.Its more natural too

Rumpleforeskin · Jan 13, 2008

18/6 is great if you don't mind growing your weed slower.

SSH · Jan 13, 2008

24/0 for first week or two to get a jump on growth then switch to 18/6.

chubbynugs · Jan 13, 2008

SSH said:
24/0 for first week or two to get a jump on growth then switch to 18/6.

Why not also have that jump in growth after that first week or two? I am all about the 24/7 schedule especially since i pull nugs like this in my veg closet.Masterlow

GHETTO_grower · Jan 13, 2008

pretty sure 18/6 shows the sex faster

bugbud63 · Jan 13, 2008

I like 24/0 for 1 week under 4' shop light ,then 18/6 when using hid lights or CFL's.Whats funny is if i use cfl's from the start they dont grow very well at all,until about 1 week old,the shop light is much faster(just a reg 4' shop light).I believe its becase of too much heat from the cfl's which in turn drys the soil very fast and can burn them;I keep 27 watt cfl's about 1'' from tops.Good Luck.Stay Safe!!

HeadyPete · Jan 13, 2008

If I don't use 24 hr light my LUI mom will flower. They like to autoflower and will under anything less than 24hr.

WaywardBob · Jan 13, 2008

GHETTO_grower said:
pretty sure 18/6 shows the sex faster

3 of my 5 plants showd sex in 20 days from seed under 24/0.. i thnk thats pretty good isnt it? maaybe i had to genetics, never gone 18/6 before tho..

facelift · Jan 14, 2008

I read somewhere that plants need 1-2 hours of dark to improve photosynthisis.

18 or 24 hours of light

Active member

Member

Member

Guest

Member

Active member

Member

Member

*********

Member

Active member

Dirty hippy Bastard

Member

New member

Registered Pothead

Active member

Member

Take Five...

Member

This is the money you could be saving if you grow