Hey, I just discovered someone using plastic bird tree netting or deer fence. I guess anything with plastic can do it. It looks much cheaper too! I'm sticking to scrubby pads.
http://www.doughtywatergarden.com/Tips/55 Gallon Biofilter.htm
I figure my cost so far for 1 drum is:
$35CDN for the 55G barrel (I know a place that sells 'em used, but I hear some people buying 'em for $5 - impossible for me... don't have the connection).
$100 bucks in scrubby pads. I thought I was gonna be able to do it for $50. :-( 5 bags will occupy 1.9 gallons. 100 bags will give me 38G. I guess with gaps, it should be more than enough.
The big question for me is plumbing. Probably another $50-100 in plumbing.
My pump will be an Eheim 1620 (900GPH). I love Eheim pumps. I have 3 smaller ones for my reef tank. Have one for 20+ years, and still running strong, but on second impellar. Small crack in magnet but still worked. Not taking any chances though.
I just posted a message on another thread asking why everyone likes to pump their 55G barrels from the top down and not just tap a hole at the bottom instead!? I don't know why, I think water pressure would still be the same eitherway.