Lights on at night when it the coolest

PhishPhood16

PhishPhood16

Well-Known Member
I have a 4x4 tent with a growers choice roi-e680, the room the tent is in, is pretty much blacked out, except where the exhaust kicks outside. Southern California is going through another heatwave, and my central air struggles to keep the room at 80°-82°F at lights off. So I run my lights at night for veg, and the tent keeps at 74°-76°F. I been researching, without much success, how plant grows with warmer periods of darkness, than having the lights on at a cooler temperature.
 
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go go kid

go go kid

Well-Known Member
IM NOT SURE ABOUT THE EXACT TEMPS THAT STOP PLANTS GROWING, someone will chime in, but as long as theres no light getting in through the ducting you should be good to go
 
Moflow

Moflow

Well-Known Member
I believe the greater difference in the temperature between lights on and lights off the more stretch you'll get in flowering.
If that helps. Cannabis can deal with a wide range of temps.
We've a bit of a 'heatwave' here too in the UK and my flowering area was 36°C - 96°F the other evening.
Ì normally have to deal with Low temperatures in the grow rooms. Around 23°C - 73°F lights on down to 12 - 14°C lights off in the winter.
Ì use leds. The optimum room temperature for growing with leds is ~ 83°F so you are ok.
My plants are doing ok, just drinking more.
 
Moldy

Moldy

Well-Known Member
Moflow said:
I believe the greater difference in the temperature between lights on and lights off the more stretch you'll get in flowering.
If that helps. Cannabis can deal with a wide range of temps.
We've a bit of a 'heatwave' here too in the UK and my flowering area was 36°C - 96°F the other evening.
Ì normally have to deal with Low temperatures in the grow rooms. Around 23°C - 73°F lights on down to 12 - 14°C lights off in the winter.
Ì use leds. The optimum room temperature for growing with leds is ~ 83°F so you are ok.
My plants are doing ok, just drinking more.
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Ah, I saw the British Open was at 80F on Sunday, I guess it was a record temp. I'd love an 80F day, damn average temps are 87F here so far this year in the NV desert with heavy smoke, ash falling from Lake Tahoe Tamarack fire. 14 days in a row above 100F. Ugh! Not starting the grow until Sept. but then I get 3 harvests before the heat and smoke of spring.
 
Moflow

Moflow

Well-Known Member
Moldy said:
Ah, I saw the British Open was at 80F on Sunday, I guess it was a record temp. I'd love an 80F day, damn average temps are 87F here so far this year in the NV desert with heavy smoke, ash falling from Lake Tahoe Tamarack fire. 14 days in a row above 100F. Ugh! Not starting the grow until Sept. but then I get 3 harvests before the heat and smoke of spring.
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Yea it's unusually fecken hot for here for 55°N UK
2 days ago It was 31.2 °C - 88.16°C in Ballywatticock!
What a name lol.
Nobody had heard of Ballywatticock until it broke the highest temperature ever recorded in NI.
You are getting it bad compared to here with the heat and fires. Over 80 fires across the West, people being evacuated.
Then look at Western Germany and Belgium and the terrible flooding.
 
mudballs

mudballs

Well-Known Member
go go kid said:
IM NOT SURE ABOUT THE EXACT TEMPS THAT STOP PLANTS GROWING, someone will chime in, but as long as theres no light getting in through the ducting you should be good to go
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@0:43 jorge says growth drops 80% above 85deg...personally i do not subscribe to that so id say it's more like 95deg it starts to slow down.
 
Wet Socks

Wet Socks

Member
mudballs said:
@0:43 jorge says growth drops 80% above 85deg...personally i do not subscribe to that so id say it's more like 95deg it starts to slow down.
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Adding CO2 when temps hit the high 80's mid 90's helps no end.

When I'm vegging I aim for low 90's with CO2 running and RH in the 80's. The growth is insane.
 
Star Dog

Star Dog

Well-Known Member
PhishPhood16 said:
I have a 4x4 tent with a growers choice roi-e680, the room the tent is in, is pretty much blacked out, except where the exhaust kicks outside. Southern California is going through another heatwave, and my central air struggles to keep the room at 80°-82°F at lights off. So I run my lights at night for veg, and the tent keeps at 74°-76°F. I been researching, without much success, how plant grows with warmer periods of darkness, than having the lights on at a cooler temperature.
Click to expand...
Plants grow during darkness using starches stored through the day they don't stop growing.

Keeping day night temps close reducing stretch is pure bro science.
 
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