Commercial biofilter media is expensive, far more expensive, in my opinion, than it should be. The media chosen must allow free flow of water and not become easily clogged, be easy to clean when necessary, and be CHEAP. In this filter design I have used 200 psi ¾ inch pvc pipe, cut into 1 inch pieces. While cutting a 10 foot piece of PVC pipe into 120 pieces can produce a few blisters, it is a relatively cheap way to make bio media. I accomplish this task using a miter saw. Cost is about $15.00 a cubic foot, as it takes eleven 10 foot pieces of 200 psi 3/4 pvc to make a cubic foot of media. Per my calculations, one cubic foot of such pvc pieces provides 56 square feet of bio film area. This comes to 3.73 square feet of surface area per dollar. For comparison with commercial bio media, Bio-Barrels are available that provide from 26 ft2 to 64 ft2 per ft3 at a cost range of from $31 to $55 (average about 1 square foot per dollar). Commercially available Bio Balls provide from 98 ft2 to 160 f2 per ft3 for a cost range from $26 to $39 (averaging about 4 square feet of surface per dollar). The commercial bio Balls provide about the same surface area per dollar than the pvc in a smaller package, but they are harder to clean than the pvc.
Here are three bags of the filter medial made up of 1" pieces of 3/4 inch 200 psi pvc pipe. Be sure to rinse the media before installing.
Putting the pvc pieces in nylon bags makes them easy to handle, easy to remove, and easy to clean when necessary.
