I just redid my 100 gallon with 150 pounds, basically. The bottom layer is 18 liters of Amano Power Sand from the 2007 auction, a thin layer of peat, then 60lbs of Turface. I did not rinse it, but just kept filing and refilling the tank until the water was clear. A lot of air was trapped in the layers, but I jiggled the substrate around the let it out. Some air will be there still, but I don't think it's a bad thing, the plants roots might actually like the extra oxygen. Susan _______________________________________________ GSAS-Member mailing list GSAS-Member@thekrib.com http://lists.thekrib.com/mailman/listinfo/gsas-member