I have a six inch fan that moves 240 CFM. Grow tent is 50 by 50 by 79 inches, so that’s approximately 114 Cubic Feet. (If my calculations are right. So, I’m thinking that’s a good amount of air to be moved in and out and should take care of the higher temperatures caused by the lights. (Especially the HPS)
Two lights. 1 400 Watt HPS and 1 300 Watt LED. I’m thinking that I should have the fan on the same timer as the lights so that I don’t have a fast drop in temperature every night when the lights go out. I also have a couple of 5 inch “corner” fans that fit just right in the bottom of the two fan holes. This fan I might be able to leave on. I’m running temp tests as I type this and it will all depend on what I find in my hourly temperature checks. (None of my good plants are in the grow tent yet, just my two bag seed buddies.)
I’m also thinking I might set the HPS on 75%. I know that’s not exact as far as how much light the plants will get, but it’s closer than 100%. And I don’t think I need that much anyway. I’d just like to see if I can get them to grow a bit faster and bushier with the extra light.
So, my questions…
- Fan on full time or with light timer?
- HPS on 75% or 100%.
- Am I moving enough CFM?
- Once the grow is over and I want to use the tent as a drying station, is the fan sucking too much air?