Cheap bio-media

     >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.