My grow tent is in a basement. The platform is off the ground… but in the winter like now, the air is typically 62 F.
For the time being, I have a thermostat controlled heater at the bottom of the tent and a filter exhaust intake on the top exhausting outside the room but running at a fixed speed…
I plan to upgrade for next year but for the time being here’s what I get as a temperature range: Temperature fluctuates based on the cycle of the heater: 74 F to 86 F
This cycles up then back down then back up again every 21 minutes.
Is this okay to fluctuate 12 degrees like this? After all, isn’t that what happens in nature?? Without the heater it’s a bone chilling 62.
Which is better always 62 or 20 minute cycle up and cycle down from 74 to 86?
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Every 21 mins it changes 12 degrees ? Thats probably not good tbh. 86 is already hot even for sativas
Nah nature doesn’t cycle 12 degrees every 21 mins back and forth. Need some kind of shut off for the heater or something. I live in a subtropical climate and my temp doesn’t change that much.
Thermometer in sun is 15 degrees higher than in shade. Solar radiation.
Clouds rolling in have same effect although air temperature is the same.
Wonder what this all means?
Anyone experimented? Or had grow results given this fluctuating?
If your climate is too cold (like mine), or too hot, and you think that the only option for you is indoor cultivation, think again. The acceptable outdoor marijuana temperature range is quite wide, and marijuana plants, at least mature ones, can be surprisingly hardy. As a result, they can take a lot of bad weather and still reward you with enough high-quality buds.
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10 to 14 degrees differential lights on lights off is fine. With the swing every 21 minutes, It would be best if you had a lung room that you controlled more stable temperature to pull your fresh air from. Just my thoughts good luck neighbor.
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Thank you everyone for the advice.
I decided to forgo such an experiment . Not worth the risk. So i unplugged the heater and we’ll just go back to slow growing at 62.
Better to have lower yield than to kill them and have none.
Thanks!
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I am also a basement grower using A tent Inside I framed off 10’x12’ room which I can control my temperature within a couple Degrees. So lights off your Temperature is 62 to 64 an lights on 72 to 74 that’s not a deal breaker.
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@kellydans
Tent lights only on= 64
Tent lights + exhaust + heater cycle = 74 to 86
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Inkbird makes a good temp controller that you plug your heater into and it turns the heater on and off to keep the temp in the range that you set. Amazon has them for around $30 usd. This keeps the temp in a tighter range as most dials on heaters range 10-15 degrees from when they click on to when they click off. This also allows control of the temp drop from the lights turning off a lot better.
Is the big fan for your ventilation system equipped with a smart controller or just a dial knob?
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It’s got a smart controller but I have not explored that yet
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I have a smart controller for mine and have it set to 1 during lights on and 2 during lights off till I get an oil heater and 4” duct fan. YouTube should have some tutorials on how to set up your controller.
My tent stays at 77-78 during lights on and 66 during lights off. My RH jumps up 10 during lights off too
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Wow ! Lights on only 64ﾟ May I ask what kind of lights they must not be putting off no heat at all.
@kellydans
210W input LED in a 3x3 tent. The lights give off decent heat but
Problem might be I’m exchanging too much air. I have the large flap open at the bottom with a fan blowing in cold air from the floor.
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@VirginiaGrowBoy Try opening one of the 6" holes at the bottom. Close the large flap hole, Turn off the inlet fan an let the exhaust fan do the work. Monitor the temperature an see if you can maintain some of that heat off the lights when on. Also if not already run your lights at night an off Daylight hours.
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@kellydans
Thanks!
I’ll give your idea a shot Tuesday evening when I have time to get to it then. Thanks again. 
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