I was familiar with Walstad, but that thread was enlightening. Thanks. So how does this sound for substrate--a little red clay, topsoil from my yard (I'm in luck! I'm digging a pond soon!), --maybe--a handful of oyster shells? Heard mixed things on that. Then sand. The plants are going to be--Ozelete sword, pygmy chain sword, dwarf hairgrass, various rotalas, watersprite. Probably a few small kinds of crypts. Lighting--2wpg, CO2--DIY. Sound good? I've never done tank exactly this way before, though I have used soil--kind of (long story).