315 cmh in a 2.5x2.5x6

Renfro

Well-Known Member
195 CFM? what exact fan is it? Some do better than others at actually achieving their rated CFM in a real world application.

The ambient (intake) air temperature is the key. Can't cool a warm space with warm air. If you are exhausting the heat into the same area you pull the cool air from then unless you have an AC in there you will heat up the intake air diminishing the cooling capability of your system.
 

JoeBlow5823

Well-Known Member
Should stay plenty cool. Like Renfro said, the thing about temps that matters the most is the air going into the tent... If the air going in is 70 degrees, a single 195cfm fan should easily keep you under 80. You will be right at 50w/ square foot should have some very nice results. Your tent is 37.5 cubic feet. Under perfect conditions you would be exchanging all the air in the tent every 12 seconds. Even if you are at 20% efficiency on the fan, you will still be exchanging all the air every minute.
 

cryptogrow420

Active Member
I have a 315 Watt CMH in a 2x4x6 and it is doing well. Temps can get a little warm during the day so I am running my 12/12 lights from 5PM to 5AM to help with the heat. I have a 6" AC Infinity with carbon filter and it has enough CFM (402 CFM) to do 2 tents this size. Nice thing about the AC infinity fan is they have high heat and high humidity triggers and ramps up with the controller.

1 Week into flower.

Left side Dog Walkler OG, Alien Cookies top middle, Gorilla Glue #4 (might be a male dont know yet) and the top right one with the huge fat fan leaves was bag seed from the same as the Alien cookies and they look nothing alike so who knows. Dont know the sex on that plant either. But so far 3 Females. Plus I have a 2x2x5 veg tent with several feminized plants going to throw in the flower tent once ready.
 

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Patriots781

Active Member
How tall is the tent cause I run my lights there autos fro. 8pm to 12 pm the next day I got a 32x32x72 and my plants grew to 30 inches not including the pots and the highest I could get the light up was about 16 inches maybe away and it was too hot and I had and intake fan 270 cfm and a strong exhaust fan
 

Patriots781

Active Member
How tall do you grow your plants cause usually I grow 3 feet plus at least a 12 inch tall pot and with the size of the light as high up as it can go it laves me like I said about 16 or 18 inches but if you top which I probably should have done but your also using a pretty strong exhaust fan or maybe its the extra width or length idk
 

cryptogrow420

Active Member
This is the first time I have grown in this tent so not sure as far as height but I’m expecting these to double in height. But this CMH light is powerful and the plants love it and are not stretching bad at all. and I just flipped the lights a week ago so we will see. I took these pics today. I feel I have lots of room I can even move my light up more if needed. What style CMH lamp don’t you have Vertical or horizontal bulb? I have the vertical style hood and with this style you can get much closer to your plant tops. 18-20” no lower.
 

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