Cold temperatures while lights are off

Afgan King

Well-Known Member
Plenty of posts, 1 or 2 actual suggestions as usual...

I have the same problem and I would love it if someone had a solution to this. I have used a small (pc fan sized) heater fan from ebay, which works okay, but I'm kind of hesitant to leave it on at night because fire hazard. An alternative might be using an aquarium heater in a water container, to serve as a small radiator. They are often variable and shouldn't be hazardous to leave unattended for hours.
Your grow is fine down to 58° at night
 

8/10

Well-Known Member
I can't remember the numbers from the last grows and I just planted a new grow today, but in the past I've had trouble staying within range of recommended temp and humidity to prevent bud rot and big temp swings between day and night. I have a dense canopy and temp and humidity is crucial, so I could really need some good suggestions on this issue.
 

Afgan King

Well-Known Member
I can't remember the numbers from the last grows and I just planted a new grow today, but in the past I've had trouble staying within range of recommended temp and humidity to prevent bud rot and big temp swings between day and night. I have a dense canopy and temp and humidity is crucial, so I could really need some good suggestions on this issue.
Well I never have bud rot my temps day can get high 70's and night time is like I said 58-61. So I have a 20° temp swing with no issues of it. Keep humidity low I do 35% you'll see an expression from your plants that you'll love and same with running cooler temps any questions I'm glad to help, how many fans you gonna have? Keep good air movement and do selective pruning to allow air movement to everything.

Edit: it's not always a 20° swing my canopy runs at 75°on average
 

CobKits

Well-Known Member
it will stunt. get a big ass res in the same area and a res heater to 70 degrees. will help a bit. roots hate 50 degree water
 

8/10

Well-Known Member
Good to know those conditions doesn't always bring bud rot, Afgan. It's pretty similar to my grow, but I have a very dense canopy in a very small space and I believe the bud rot comes from the combination of temps/humidity and dense canopy, so I need to keep conditions as unfavorable to bud rot as possible. Last grow I had one main exhaust fan, 4 pc fans and 15 tiny fans permanently mounted on my lamp. The canopy was as dense as it can get and I barely managed to escape BR. I had a tiny amount but chopped it and the surrounding buds before it got anywhere.

Cobkits, great tip.
 

elfo777

Well-Known Member
Bud rot triggers when humidity is high and temperatures are low. I'd say low temperatures are ok, but if you get high humidity it will trigger for sure. When lights are on I get only about 40% humidity, but when the lights go off, I can get as high as 80%. That's why I bought this:

https://www.amazon.com/Pecute-Reptile-Infrared-Ceramic-Appliances/dp/B00NONWD5U/ref=pd_lpo_199_lp_t_4?ie=UTF8&psc=1&refRID=615GT1ZTPF8V7WDH0H2E

Depending on wattage it can keep a grow tent warm and most important, the heat will keep humidity low and temperature at about 60 fahrenheit. That's the only thing that worked for me...
 

Afgan King

Well-Known Member
Bud rot triggers when humidity is high and temperatures are low. I'd say low temperatures are ok, but if you get high humidity it will trigger for sure. When lights are on I get only about 40% humidity, but when the lights go off, I can get as high as 80%. That's why I bought this:

https://www.amazon.com/Pecute-Reptile-Infrared-Ceramic-Appliances/dp/B00NONWD5U/ref=pd_lpo_199_lp_t_4?ie=UTF8&psc=1&refRID=615GT1ZTPF8V7WDH0H2E

Depending on wattage it can keep a grow tent warm and most important, the heat will keep humidity low and temperature at about 60 fahrenheit. That's the only thing that worked for me...
Agreed which is why I said put it at 35% if u can. 35% day 45% night never an issue ever. It's higher humidity and low air movement with highly fluctuating temps that cause it IME. Any pics?
 

CobKits

Well-Known Member
Cobkits, great tip.
not too warm or you risk root rot but a 70 degree res is a lot of thermal mass and can take the chill off your tent for sure. and it will be radiating heat out the sides all night. it could make the difference of upper 50s vs lower 60s in a room/tent depending on airflow
 

SPLFreak808

Well-Known Member
Hello.

Im growing indoors in a very cold house, temperatures can get as low as 55º fahrenheit while lights off. Winter is coming (heh) and im worried that it may kill my plants.

I was wondering if this is dangerous for my plants or cannabis can tolerate temperatures this low. I have a black ceramic heating bulb so I can use it to raise my temperature up to 60-65 while lights are off.

Is this enough or shall I be worried?
You could use lights at night and dark hours during day time if you wanted a little temp jump during dark hours.
 

researching

Well-Known Member
I run little to no heat in flower room. I prefer temps like AfganKing goes for. I like the color change and the benefits of cooler weather. More realistic swings too.
 

Afgan King

Well-Known Member
I run little to no heat in flower room. I prefer temps like AfghanKing goes for. I like the color change and the benefits of cooler weather. More realistic swings too.
Yup yup if humidity stays stable your ok with cool temps it's just humidity swings that fuck shit up my does 15-20° changes day to night sometimes never an issue 35% humidity
 

researching

Well-Known Member
Yup yup if humidity stays stable your ok with cool temps it's just humidity swings that fuck shit up my does 15-20° changes day to night sometimes never an issue 35% humidity
Mine is very similar. Although with my new setup I am seeing higher overnight humidity. I am controlling it fairly well but a dehumidifier is in order. I prefer growing in cooler weather. Not just from an efficiency perspective but a quality/appearance perspective.
 

Afgan King

Well-Known Member
Mine is very similar. Although with my new setup I am seeing higher overnight humidity. I am controlling it fairly well but a dehumidifier is in order. I prefer growing in cooler weather. Not just from an efficiency perspective but a quality/appearance perspective.
Less issues as well with insects
 

elfo777

Well-Known Member
Mine is very similar. Although with my new setup I am seeing higher overnight humidity. I am controlling it fairly well but a dehumidifier is in order. I prefer growing in cooler weather. Not just from an efficiency perspective but a quality/appearance perspective.
So you think growing in cold conditions increases bud quality?
 
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