Humidity and Heat Control

Hey all!!! New grower here and got a humidity and temperature related question. I have a 3x3 tent with inline exhaust fan and 2x 150watt led lights and a clip on fan. What I’m running into is my heat and humidity is a little wild. When the lights are on at around 60% my heat is hanging out around 83-86 degrees even with the exhaust duct fan running. I was getting some fairly low humidity (35%) so I put a small humidifier in there but even at the lowest setting it’s pumping humidity up over 65% and heat is still cooking around 84 degrees. Fahrenheit by the way.
So the question is should I add an intake fan to help cool it down along with the clip on fans??? And should I get a smaller humidifier to get it down a little bit??? What are your thoughts on how to get this setup a little more in the sweet spot. Or is that a decent sweet spot already. Like I said new grower here. First official grow and I wanna start on the right foot. Thanks in advance for any and all insight.

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I don’t worry too much in veg what the RH is. Your temps are getting up there but not out of control. Ideal is 78 to 82F. Assuming a full grow space, when you get into flower you will need to remove humidity. That’s the time to really adjust your grow parameters. Too humid and you will fight White Powdery Mildew (WPM) and Bud Rot.


Ok that’s awesome to hear!!! I’ll probably kill the humidifier than to save a little energy. Thank you so much for your insight!!! I appreciate it!!!


Dialing in a tent can be challenging. But it’s actually very simple you need 4 things. Heat, cool air, and humidity, fresh air

I find the best way to set the tent up is to first bring in cold air. I do this by simply hooking up a window unit and running a duck right into the back of the tent straight on to the floor now I have air conditioning in my tent. When you need the cool numbers in your tent turn on the air.

Second I go to the heat and it’s very simple a little portable ceramic heater with a thermostat will heat your tent perfectly.

Without anything in my tents it’s 94°. So let’s say I need to get to 70°. I simply turn my air condition on and set the heater to 70 boom 70°, as long as you need it. And yes it’s that simple I’ve been doing it for a long time I don’t have any thermostats that I play with except for the one on the heater all you’re doing is compensating cool air.

As far as humidity goes I could not dial my tent in with humidity with any of these Vicks vapor rub things. So I built a commercial grade humidifier. Cost me about $100 to make it.

Other than that a nice exhaust fan and a couple oscillating fans for your poles and you’re all set.

I grow nothing but autos so I don’t need to worry about darkness and light leaks the point of this is on the left and the right side of the tent on the floor are two vents with velcro I pull them off and I have two 6 in fans blowing in there that keeps fresh air pumped into my tent.

It all seems complicated until you just think it out. it’s actually a very simple effective way to dial your tent perfectly.

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Look into getting an Inkbird controller if you’ll be using two competing appliances together (IE: Heater and AC). , Make sure they have the memory ability to return to their previous settings after a power outage and turn them to always-on. Then just plug them into the Inkbird, and make all settings from there. The Inkbird will power up the appropriate appliance at your setpoint, factoring in any desired offsets.

Newer fan controllers, like AC Infinity and Vivosun brands can also act as a hub, and with additional adapters, also do the same thing instead of an Inkbird.


Found these somewhere when having similar issues.
Have Fun and good growing to you

Dialing in is so easy and fun, I sleep while lights are on (separate spaces).
Fortunately we have a good weather man for PNW, cause the weather is always influencing my grow.

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That is amazing info!!! Thank you for that!!! It’ll help tremendously.

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