>First, I have (of course) read the krib archive about cheap
>bio-media, and was interested to read that most people have opted for
>non-porous material like chopped up drinking straws etc, surely the
>objective is to achieve the greatest possible surface area/volume.
>ould not something like smashed up terra cotta plant pots or other
>fired ceramic material do the trick more effectively?
I use crushed lava rock, 1-2 inches in diameter. It's cheap ($3 for
30 lbs), porous, non-calcareous and available in most garden supply
stores. I got mine at Home Depot.