A couple inches clearance. 10” height total height. 8 inches of water? One inch of sand maybe, maybe not. May do barebottom with a bottom drain to keep it clean, may drill in from the side. Undecided. I’d like some sand or smooth small gravel for them, or I may just build up some substrate on one side, since it’s such a low aquarium it’s ideal for growing a carpet.Perfect then! How high is that lid compared to the water level?