well, i got a bucket full of sand from lake ontario and some big slabs of rock with a few fine pieces of driftwood. i want to setup a tank with the sand. i know about cleaning it and stuff, no problem. question is, how do i keep the sand clean of fish poo when the aquarium is established? like, do i use a gravel vac or something? the poo will in all likelihood get mixed in with the sand so how do i keep it clear of that kind of contaminant?