Venting Down Sewer Question

Oh I agree - it is VERY unlikely you'd have any problems on a mid size grow.
I'm just sayin if someone reading this wanted to vent a full basement grow, using a furnace blower to try and force it up a 3 or 4 in pipe might cause a problem.

My clean-out is located in the floor right next to my grow closet. It would be crazy simple to hook up a backflow valve and a 6" flex pipe to it. It is well past the traps. So, if I have fresh air coming into the closet near the floor, and pull air through my reflector and then down the sewer, I'd be all set, right?

Should be all good...