I’m past 85 degree temps. Pulling the cool air (adding the extra fan) through solved this problem. I can now go sub 80 easily. Really only limited by noise now. Plants are about 3’ tall now and just starting to flower. Had to back off all nutes as soil is FF ocean and anything I added burned them. Also gone to straight tap water (no php adjustment) as my php run off is about right,
Can you mount your exhaust fan up high? Right now, it has to pull that hot air down across the plants before directing the exhaust back up.
Also, I don’t use that kind of light, but I’ve seen others’ grows where the fan is actually set-up to directly exhaust the light.
Yes I can add ducting to pull the air from further up. I bought a carbon filter and planned to install it but so far I have no problem with smell as the closet is air tight and the venting is thru a turbine on the roof which is quite high,
The setup now works pretty well. Always room for improvement though.
You want your intake down low, and exhaust up high. That will really help with temps & air flow.
Do you have a fan pulling air through the duct attached to your light?