I've read somewhere that bricks and earthenware pots are basically laterite. Could one "produce" aquarium laterite by smashing up some red clay pots? It'd be cheaper than dupla. :) Hey, if you don't go all the way, you have your own "laterite shards" which can be pushed into the gravel just like DuplaRit K. What do you think, sirs? --- Erik D. Olson olson at phys_washington.edu