There's plenty of DIY scrubbers online in forums but this is ideal for my setup, which is a small 2x2 tent with LED's where I grow 1 plant at a time, and temperatures in the high 70's. This will not work for a larger tent/room with higher ventilation needs or higher temperatures to control (i.e. CFL or HID) I don't need some industrial strength ventilation system, but I do need SOME ventilation and odor control. I had ventilation with my fan, but things were getting stinky. For this you will need a small household fan, roll of aluminum flashing, duct tape, a sheet of carbon filter material (cheap on amazon) and preferably tin snips to cut the flashing, or wire cutters will work. Step 1: roll your aluminum flashing around to about 2-3 sheets thick in a circle that matches the diameter (or close to it) of your tent's exhaust sleeve Step 2: cut with tin snips or wire cutters and use duct tape to hold its cylinder shape intact. Step 3: cut a piece of carbon filter material and wrap it over one opening of the aluminum cylinder. Cut notches around it to allow for folding the piece onto the sides. Duct tape the filter to the cyclinder. Step 4: chop up a bunch of bits of filter material with scissors and toss them into the cylinder on top of the filter "bottom" Step 5: place into your tent's exhaust sleeve and tighten the cords as much as possible Step 6: place the household fan on top of the cylinder as tight fitting as possible (mine cups into the opening perfectly) and turn it on I can report that this has eliminated odors both during operation and lights off time as well. Pictures below: