We were out and about at the lfs, and i happened to get the crazy idea of doing a planted for my then empty 20l.....well 200$ later the tanks finally set up with kitty litter substrate (first time for me) t5 dual bulbs, and some driftwood. I didnt put sand or gravel over the kitty litter and now im worried that it may need it as the substrate seems spongy....anyone have any experience with strait kitty litter? Its definatly unscented and is the strait clay stuff. Isit supposed to stay spongy or will it settle over time? Tanks only been up and cycling for two days, the water is clear, and all seems ok i just want to make sure i dont need to tear it down and redo it before adding fish.