I'm not finding much online to help me with this exact situation. Have 8 x 4 grow tent with 2 large oscillating fans blowing on opposite sides across each other (crossing at different times). I leave them on full time when lights are on (18/6) & let them rest about 3 times for 30 minutes in dark time. I also have the tent vent windows, at the bottom on opposite sides, open 24/7. My humidity ranges are always pretty solid, except at night they really spike up but I do plan on using a dehumidifer when I get to flower in a few weeks.
That's where my question comes in. I'm going to 12/12 for flower in a few weeks & I realize that I need to avoid any light source on the plants in lights out. So do I close both tent flaps during flower & rely on the inline fan (8" AC Infinity Cloudline w/ controller) and oscillating fans to do all the work? Right now the T8 is just set up to kick on when the tent reaches 79 degress which is every few minutes. Hopefully that is the best there too? It's possible I could leave one tent vent open because it faces a basement wall where there is no light. Should they both be closed during flowering. Or do you guys even close them during veg stage too? What is the best option - both flaps closed, one flap open or should they be closed altogether near the end of veg? Anf am I utilizing my AC inline the best way to kick on at 79 degrees if that is near my top temps?
Thanks!
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Ok, I just readjusted my controller for both high temp and high humidity so the inline fan runs more overnight to drop that RH. I was topping over 80% for a couple hours every night. Changed it so fan kicks on at over 65% during veg. Then probably 50% during flowering. Thanks for the heads up on VPD. Something I was unaware of until reading up on it.
Unfortunately v.p.d. comes into play alot here. If I notice my humidity staying high at night I will leave my exhaust fan "on" but set at like 5 or 6. This should help keep it down enough to not need a dehumidifier. With keeping your humidity low though, in turn the plants will transpire more, and you may or may not want that. If light is an issue with your vents, then I would close them and set my intake and exhaust fans to keep air circulating. Set them to keep a slight positive pressure ( tent shouldn't suck in, or blow out).