I asked my LFS about how to convert a 20g freshwater to a clownfish tank. The advice that they gave me was how I planned on converting the tank. It already has a 107, with a spray bar, hooked up. I can get the live sand there, I've seen it before. I'd need to buffer the ph with rocks, but I don't need live rock. Would Texas Holey Rock be fine for them? It'd look rather striking with my plan of black sand. I also plan on getting some crushed coral or aragonite to put in a bag in the filter, that would also help to buffer the ph.