85* to 90*F is the temp range where C.Sativa stomata on the plant are wide open. Anything lower and the stomata close more and more. We want the stomata wide open so they can suck in lots of CO2.
I agree with Mr.T though, these temps are too high for unchilled hydro in most cases. Running Co2 is no small thing, it takes a pretty dedicated grower and lots of coin to do correctly.
So let me ask you this, should I let my temps rise then? I've been running CO2 for over a year now, but my winter day temps max out at 77 tops. Am I wasting it then? I never heard this. I just heard you CAN go that high.
I would try it higher if they will take it, yes. I gree with B. friendly though, it can be strain dependent, and for most purple strains you want to run them cooler towards the end so they color up faster. Most guys taper off their CO2 in the last couple weeks anyway, as high CO2 inhibits ethylene production, which is what causes ripening. Drop it to about 600 PPM in the last two weeks for best results. Also, new studies have shown that weed can't assimilate more than about 1000PPM of CO2 overall, so you only need to supplement about 700PPM instead of 1200.
Well when temps hit 80's Cannabis metabolism is moving faster there for she can eat more her stomach is wide open.. if you play music its proven to open up their stomaches too...I used to keep it around 80's 85 87 in a sealed room with 1500ppm at all time and used to get at least a lb per light sometimes almost 2 in each room of 14k lights...
Sealed rooms are the way to go no pest unless you bring em in you can kill spider mites by rasing ppm to 3,000 and keep the smell in one room.
hope this helps.
Well when temps hit 80's Cannabis metabolism is moving faster there for she can eat more her stomach is wide open.. if you play music its proven to open up their stomaches too...I used to keep it around 80's 85 87 in a sealed room with 1500ppm at all time and used to get at least a lb per light sometimes almost 2 in each room of 14k lights...
Sealed rooms are the way to go no pest unless you bring em in you can kill spider mites by rasing ppm to 3,000 and keep the smell in one room.
hope this helps.
If you drop the CO2 ppms to about 600 overall during the last few weeks, ripening will accelerate by roughly 5%, or a few days typically. Shaving off a few days means the next crop can start a little sooner, a good thing in commercial gardening!
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Thanks for that tip Lazyman! Its hard to find bits of knowledge like that on here. Not many people like to use the word "commercial" in their posts.
Well put, and I know full well how hard large rooms are to dial in. I run two 8KW grows perpetual fashion in the same room, one harvest per month. The 8-light yields have been as low as 3.7#, and as high as 14#. Averaging about 12 now though, which I am not upset about.
Looking at them as 4X4KW, my best "row" was on my last run at 1.78# per light without CO2. Now that I have a good idea of what it takes to yield well with my setup, and I'm fairly comfortable that she can't do much more (the genetics are the only thing that changes now) it's time to add CO2 and hit the big, red "TURBO" button. Not looking forward to the initial AC purchase at ~$15K, but I hope the added yields will cover it in approximately 2 months though. After that it's just an extra 2.4# a month or so (figuring a modest 20% yield increase) as gravy on top.
If you drop the CO2 ppms to about 600 overall during the last few weeks, ripening will accelerate by roughly 5%, or a few days typically. Shaving off a few days means the next crop can start a little sooner, a good thing in commercial gardening!
Just wanna throw in my two cents, I agree with pretty much all Lazyman said.
EVERYTHING is strain dependent, but you can easily gauge how hungry your girls are by the amount of water they are sucking up.
When I hit that 3rd-4th week of flower and can't keep enough water to the girls is when I have the CO2 all the way up. When their thirst starts tapering off I start cutting back the CO2. From everything I have read, seen, and done you do need to increase your temps when using CO2 to get the higher yields. In my experience increasing feeding during this time period also can help top out your yield.