24/0 or 20/4

[Waira]

I always thought they like a little sleep, but no research on it. I'm about 3 weeks into my grow, would it be to late to switch to 20/4? I got a new timer and couldnt remember how to set it lol, so I just left at 24/0. This could have something to do with a few issues I've had. Always heard that once you set your light schedule you shouldn't change. Would 3 weeks be to long to change?

:smoking: Mizzo's called that, a small change early like that is OK, and I think in general, dropping light hours at any time is far less likely to induce stress and it's consequences than increasing it, or worse, going up and down in a short period of time....even an auto will respond negatively to that!

I run 24/0. So talking with my daughter about why i see a benefit and others don't, (lots of the stuff went over my head) but the overview is during photosynthesis plants have light and dark reactions. Light reaction turns light into energy, and dark reaction stores Carbs. Dark reaction is a misleading name because its actually happening with the lights ON. So plants can remain perfectly healthy when exposed to light 24 hours a day. They should be larger and faster in a good 24/0 environment. - This is supported by our logs.

Now the issues, If plants are HOT they will slow down photosynthesis and this is what is probably happening with some in this thread. Solution = Lower leaf temps, adequate CO2, light, and proper food is all thats required to run 24/0.

PS is the light reaction, respiration (not breathing in this case) is the dark reaction, and that is going on 24/7, as it is the energy releasing part of metabolism (not the forming of storage carb's, different gig there), when the Carbon to Carbon bonds in the sugar made during PS are being broken and the chemical energy is released to ultimately "recharge" the cellular energy carrier molecules,... at this point, all the energy consumed or released is in chemical (bond) form,...
Again, 24/0 is of very conditional benefit, several other things need to be eliminated as limiting factors before one see's significant advantage there (perhaps including CO2 augmentation), and anecdotally, I think it's mainly in the building during veg', more nodes/branches... more bud production.... I forgot where I saw this, but it goes to the diminishing returns point I made earlier... Look at what the energy cost is for a years worth of growing at 24/0 and at 18/6; for the arguably marginal increase in bud yield that extra 6 hours gives, one could have spent that same amount of $ on that 6 hours on a whole other grow at 18/6, and there's no way that yield will be less than what the 24/0, 6 hour addition will offer up,...
yes, Ca, the stomata, and VPD! I think this is part of the problem with 24/0, beyond what Hobbes laid out with the max DLI (photonic energy) that a plant can use in a day... going to what I said about all other things not being a limiting factor... Some observations from 4+ years running the Infirmary: if the stress causes the stomata to close up, transpiration halts and the whole transportation highway from the roots all the way to that part of the plant grinds to a near halt, stopping nute transport and that stifles bud production,...other side of the coin, if the stomata are open, but the VPD is really off and the plant is trying like hell to stay cool (stress factor before the stomata close up to stop catastrophic water loss), transpiring like crazy, then another problem can happen.. water and most nutes are on the same "highway", and sometimes you can get localized nute burn or toxicity symptoms from the log jam of nutrients getting hauled up there but not utilized fast enough, building and building,... the plant cannot be selective about this transport, there are no mechanisms for such a process....
There is a delicate, complex dynamic behind this balance, and there's nothing automatic about the benefits... Some of the best growers with consistently high yields here do not run 24/0... As with nute, more is not (always) better! ....Plants don't need "rest", whatever that is,... but overdriving the PS machinery is detrimental on several levels, it can even cause the chlorophyll to break down (bleaching) which is about as opposite a situation as one could make in this situation,... Screwing up the VPD, transpiration and all that, also reduces yields,... :smoking: Just some things to chew on folks,....

 

[Waira]

I forgot where I saw this, but it goes to the diminishing returns point I made earlier...

I know why I couldn't find this again, late night reading isn't the best for retention! ...it's in the quote Hobbes posted in [HASHTAG]#17[/HASHTAG], and somewhere else on site....

 

[The Iconoclast]

The place I am heading towards is a total light management system and cycle set to the maturation of the plant ,, or i will see what they have at [HASHTAG]#Poundland[/HASHTAG],, intresting thread

I've been planning a similar end but I'm thinking of some sort of root stress because my system uses redundancy in the roots I can try some weird shit without killing her. For example the giant rootball that comes out the bottom of my pot, I could cut that off entirely and the plant would have a whole pot full of fine roots, so I'm curious as to what effect some sort of massive root shock would do when it's not life threatening at all. Or perhaps I'm just too stoned right now.

 

[MidnightSun]

some sort of root stress

How about the opposite? You can try hydrogen peroxide solutions. It has an extra O2 bond that helps root grow. When hydrogen peroxide breaks down only water and O2 are the by product. Don't add to the leaves. Have fun.

 

[The Iconoclast]

How about the opposite? You can try hydrogen peroxide solutions. It has an extra O2 bond that helps root grow. When hydrogen peroxide breaks down only water and O2 are the by product. Don't add to the leaves. Have fun.

The reason I wouldn't use that even if I needed to improve my root structure, would be extra unnecessary complication. In order to determine whether something has had a particular effect you have to eliminate all other possible causes which is something that would take years. When I started I made feed charts and calculations that looked like John Nash's office from A Beautiful Mind. Now I just splash the nutrient in straight from the bottle, sometimes.

 

[growwiththeflow420]

I grow 18/6 unless I have to minimize stretch... There are several reasons when growing organic to do so in my opinion. Most of them are covered in this nice interview.

 

[The Iconoclast]

I grow 18/6 unless I have to minimize stretch... There are several reasons when growing organic to do so in my opinion. Most of them are covered in this nice interview.

That's just more bafflegab, remember this is a multi billion dollar industry. But if it makes anyone happy they should work with it, and anyway, basically she has just given another reason against using soil. Because she's pretty well enumerating all the problems that you don't get in a good hydro set up and by good I don't mean complex in fact I mean the opposite, simple (as you can see for yourself in my DIY grow test with the Mars light, which btw is going ballistic).

Doubt everything you hear about cannabis, take note of it for sure, then remember that the only information you can trust is what you see with your own eyes and the best way is first hand although second hand from a trusted source is just as good. This is another benefit to a simple hydro set up if this information is important to you like 24/0 or 18/6 then you can do this test yourself, but you'll need to run it a few times due check for types of extreme differences that can pop up. I'd run it three times then I'd have an idea, but really common sense says that a few hours of darkness is a no brainer, the plants do not stop growing at night.

But ultimately one needs to ask oneself what is it that one trying to achieve, more yield? certainly not better quality. Well almost everyone is not anywhere near the yeild they could currently get of their plant without faffing around with the light, I'd work on why that is first.

 

[growwiththeflow420]

That's just more bafflegab, remember this is a multi billion dollar industry. But if it makes anyone happy they should work with it, and anyway, basically she has just given another reason against using soil. Because she's pretty well enumerating all the problems that you don't get in a good hydro set up and by good I don't mean complex in fact I mean the opposite, simple (as you can see for yourself in my DIY grow test with the Mars light, which btw is going ballistic).

Doubt everything you hear about cannabis, take note of it for sure, then remember that the only information you can trust is what you see with your own eyes and the best way is first hand although second hand from a trusted source is just as good. This is another benefit to a simple hydro set up if this information is important to you like 24/0 or 18/6 then you can do this test yourself, but you'll need to run it a few times due check for types of extreme differences that can pop up. I'd run it three times then I'd have an idea, but really common sense says that a few hours of darkness is a no brainer, the plants do not stop growing at night.

But ultimately one needs to ask oneself what is it that one trying to achieve, more yield? certainly not better quality. Well almost everyone is not anywhere near the yeild they could currently get of their plant without faffing around with the light, I'd work on why that is first.

Right? There are so many false information about growing cannabis on the internet. For example, you don't need to buy lots of different nutrient products to have great yield. Just buy the right ones and use them at the correct application rate. I guess most home growers over fertilize constantly...

If you are going for max yield then growing in soil is not a good idea... and thats why you get those insane numbers with dwc or even coco when using salt based fertilizer. For me personally using salt based fertilizer has too many negatives but this might change in the future... who knows.

I only grow for personal consumption and barely go through more than 1 oz in 3 months so my main goal is to minimize the effort to get 1-2 oz every 3 months. I prefer to grow organic with dry amendments as this makes things easier for me. Just feed ph'd water and some beneficial bacteria and fungi every other week. I don't to lots of training besides defoliation and lollipopping... my last 1 gallon northern light auto was about 1.5 oz in about 70 days.

 

[Harry_Kovert]

2 weeks into flower I've gone from 24/0 to 20/4. Only done last night though plants already look thankful for some down time. I'll be sticking with 20/4 from here on in. As far more educated and experienced peeps have mentioned the plants will benefit massively from a little rest - I'm of the perception that my mild cal difficiency is due to the 24/0 schedule I've been running with the Telos and the HLG [340w] rather than a lack of nutes. Will report back in 7 days.

 

[growwiththeflow420]

2 weeks into flower I've gone from 24/0 to 20/4. Only done last night though plants already look thankful for some down time. I'll be sticking with 20/4 from here on in. As far more educated and experienced peeps have mentioned the plants will benefit massively from a little rest - I'm of the perception that my mild cal difficiency is due to the 24/0 schedule I've been running with the Telos and the HLG [340w] rather than a lack of nutes. Will report back in 7 days.

Glad it worked out for you...pretty interested in your final thoughts! Please report back mate.

I started my last grow with 18/6 and switched to 20/4 in early flower just to see if it makes a difference and went back to 18/6 after a week. I could not see any benefits rather then she didn't look as well as before but thats just personal interpretation. I feel that she is looking healthier and happier at 18/6. Might take a few more days to finish but less vulnerable to stress, pests and nutrient issues.

I am already starting a next grow which will be minimize the feeding using only dry amendments. Got some worm humus and biobizz pre-mix dry fertlizer and going to add some from start and top dress in early flower. I saw some pretty interesting interview with a biologists that works in the industry where she stated that most growers overfeed their plants which leads to multiple issues. And especially with autos you don't need high feeding schedules from my experience. I had a northern light auto in a 2 gallon pot with plain light mix and by the end of week 4 her leaves started to get a lighter green color... she was almost 2ft by this time. If you feed too much and give her lots of light you will run into problems in most cases I guess...