I have my tank bare bottom. My tank is 450 gallons and it makes it way easier to maintain .....if I were you I'd paint the bottom preferably black as well as the backround. My tank is completely bare with only powergeads. I've had bare bottom tanks, tanks with sand, gravel, dirt/sand, lava rock. And out of all of the tanks as far as ease of cleaning etc. Bare is best. Sand looks nice and I don't really care for gravel.