After trying out a number of more expensive substrates in the past for planted tanks, I've settled on natural fine gravel with either a potting soil or peat underlayer. I just read Walstad's 'Ecology of the planted aquarium' before trying this. I won't ever mess with CO2 injection or high tech lights and stick with the plants I'v learned will fill a tank under my low tech conditions. And they will do so....even when stuck in a windowless office (grin). Betty Goetz _______________________________________________ GSAS-Member mailing list GSAS-Member@thekrib.com http://lists.thekrib.com/mailman/listinfo/gsas-member