Substrate: Gravel vs. Sand

I always prefer sand. It may be a little bit more expensive, but it makes a world of a difference. Gravel has too much space underneath, leaving room for old food to spoil and poison the tank. Also, fish waste will gather under the gravel. This will either kill the fish, or create a frustrating cleanup for you. Sand has little space. Old food will sit on top for the catfish to cleanup, or for you to scoop out. The same happens with fish waste. Now, instead of removing gravel and cleaning it, fish waste can be removed with a net, just like the way you might scoop leaves out of a pool. Plus, sand looks better.