Venting idea

my tent is in the basement it has 2 400's that vent directly out onto a concrete wall. currently i have a 250 watt and it is not venting out of tent the temps are at 80-85f. 250w is cooled buy the fan on the filter inside tent(sealed environment co2) could i take the ducting from inside the tent run it outside the tent against a concrete wall 5 feet from other exhaust then back into tent to the light to cool the light and lower temps?

You say you are running CO2? 80-85 is suggested temps with CO2, right? I don't think the duct against the concrete would help you out too much.

well find out and yes 80-85 temps in the middle of winter here

worked lowered temp 8 degrees. air passes thru about 6 ft duct out side out tent 3 ft of it along concrete wall. 3 ft inside to light fixture. 9 ft ducting 4 in centrifugal fan 265 cfm rated at 80% power air drawn from 200 cfm filter