18/6 vs 24/0

[nimmo24lung]

What do you think is best for seedlings 18/6 or 24/0??

[Anonymiss]

18/6.

Plants use the energy they've stored during the day to grow at night.

And, of course, you'll save 25% on the running costs.

[DelBoy]

18/6 for reason above and plants use dark period to repair any damage.

[FordCapri]

18/6 for seedlings/veg stage

24/0 for clones until rooted.

[Budmore]

Im gona go against the grain 24/7 T5 propagation light for the whole of seedling & 315 par watt, 600w MH veg i could see the plant stockpiling the energy for when it hits flowering it just makes sense to me the more light more energy stored in the plant

24/7 till flowering imo

[Alchemist Of Green]

yep im 24/7 till the flip to 12/12

and iv done them all 16/8, 18/6, 20/4. and plants allways stretch more.

while under 24/7 their dont stretch as much.

[jobby2812]

yep im 24/7 till the flip to 12/12

and iv done them all 16/8, 18/6, 20/4. and plants allways stretch more.

while under 24/7 their dont stretch as much.



Pretty much this^^^. I've tried a few different light cycles and the one I am loving at the minute is 24/0 using CFL's for veg. They stay on this light cycle until they get potted up and go in the tent on 12/12.

I find with 24/0 I am actually saving a few days veg to get the same amount of nodes as going 18/6. Plus on top of that the plants are shorter and bushier. So what I am wasting in extra electricity by having the lights on for the extra 6 hours a day I can save by not vegging for another 3 or 4 days to a week (strain dependant). So is it really wasted electricity to get the same amount of nodes using the same amount of light hours yet saving a few days to a week of growing?

[alwaystoned_1]

i use 24/7 for the same reason as jobby

[lambert29]

Im with the 24/7 gang...... Used to swear by a dark period for the reasons mentioned, But once you go 24/7 i doubt you will ever go back. Easier to keep the temps right,Less stretch, tighter nodes more rapid growth and better yield

[cocogrower]

20/4 for me.

Quote from ot1;

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%

[Woody J]

A few points of note here.
For growth, plants need to photosynthesise. For this, light is needed.
People who see growth "overnight" are not seeing growth, they are seeing stretch.

I did lots of experiements too, not with HID but with T5's, cfl's and flouro's and the conclusion my experiemtns came to was that 18/6 and 24/0 would produce plants of the same size but the 24/0 would have more bud sites. Conclusion of this is that 18/6 promotes stretch.
These experiments were with White Widow clones over a long time span and in sealed rooms with and without CO2 added.

The experimenting I did with HID was with MH bulbs which also tended to end up with stretchier plants rather than the short bushier dudes under T5's.
The notion that 18/6 saves money on electricity does not hold up to in depth scrutiny due to longer number of veg days for the same end results.

The overall conclusion and my advice is to go for 24/0 with T5HO's for first 5 weeks of veg (out of 6).
Week 6, onto a 5,000k metal halide 24/0
Flowering weeks 1-7 (of 8) 12/12 dual spectrum (Sunmaster) HID. Single spectrum bulbs tend to promote tretch in my experience, Dual spec reduces it.
Last week to 10 days of flower, 10,000k metal halide.
W

[cocogrower]

Last week to 10 days of flower, 10,000k metal halide.
W

Where are you getting 10k MH lamps from and whats the brand? I usually get the 7.2k MH but would like something with a bit more spectrum to it.

cheers

[Stoney joe]

Might be dumb q but are u saying no dark till flowering? And also can u only do that with a mh bulb or cud i do the same with my duel spek bulb?

[jobby2812]

Might be dumb q but are u saying no dark till flowering? And also can u only do that with a mh bulb or cud i do the same with my duel spek bulb?



Yes and yes. I now go 24/0 from the day it sprouts out the soil until they go into the 12/12 tent. They don't get to see a single bit of darkness. Can't see why you can't use a duel spectrum bulb to veg with. People use hps for veg although mh is prefered.

[rndusername]

So as with mostly everything on here (and obviously why wouldn't this be the case as it's not an EXACT science) there's differing opinion :)

Out of interest, could you change veg time periods say a week or two in ?

[lambert29]

End of the day the best way to find out is conduct your own experiment and see what works for YOUR set up (environment). We have all ran experiments and all got conflicting results and probably because they is so many other factors that can result in fast growth, slow growth, tight plants, stretchy plants. A M/H and 24/0 veg has worked for me. But a tent in a bed room or a cupboard will probs give different results to a professional sealed grow room with added c02

[WWLover]

Sorry to but in but after reading some comments I will also give 24/0 a go for a few weeks.

[lil rasta]

someone did an experiment with various times but he concluded 18/6 gave the best yields

[rndusername]

Think that's quoted a few posts above ^^

[nimmo24lung]

Seems like nobody can all agree so I'm gonna stick with 24/0 but my plants are staying white for longer than normal

[Mr Swilly]

20/4 is best I reckon, but I do 16/8 cos I'm a tight arse and usually temps are a prob during human days, so I turn em off peak hrs.

[Woody J]

The 10,000kelvin MH bulb is a Plantmax and it came from the US.
You can achieve similar results by raising your lights during the last week or so of flower. It makes the plant think it is running out of light so to speak, so it produces more resun to cope with the expected cold that is to come.
Thats the theory anyway.

There is something important to remember here and that is different results will be obtained in different environments.
What was perfect in the room I had may not be perfect in a closet grow for example.

I equate it this way, mj CAN go without dark periods. Plants grow using photosynthesis, which needs light. So, the more light I can give, the more plant material should be created through photosynthesis. If that means running lights 24/0 then thats what I will do.
That 6 hours of dark may appeal to human characteristics of everyone needing sleep and I think that is why it is assumed plants must also need sleep.

Do your own testing, come to your own conclusions of what is best for your grow space. Either way, you will have some damn fine, home grown bud to chew on.
Oh, I dont care which way you grow, as long as you grow, because while you do, its one more of us and one less of them.
W

[gotrek]

im on 24 veg the plants just seem to getg bigger than on 18/6

[Grandad]

this was vegged under 24/0 and looks like it might yield an ounce or two.
https://www.thctalk.com/gallery/data/2264/IMG_1965_-_Copy_Copy_.JPG (https://www.thctalk.com/gallery/showphoto.php/photo/90636/title/img-1965copy-copy-/cat/2264)

[Tester]

24 hour for seedling

[nimmo24lung]

Holy shit silver looks like a outdoor plant