Cheap HEPA filters for intakes?

[Hephaestus]

More microgrow sized…

Growroom unobtanium pieces

[exhaust-port1] [exhaust-port2] V2 of the hack it in exhaust fans. Basically designed to take a 5015 fan (standard style not blower) bigger like 5020/5030 if you have a thicker than 2mm panel to go through. Meant for the inadequately tooled diy’er. Basically if you can hack a hole bigger than 2" and smaller than 4in and apply some double sided sticky tape or glue… Mostly lightproof exhaust. V1 had some extra baffles, but they restricted flow way too much. Now if I could only figure out why…