If your just using a sponge filter you're good to go, but if you go hob you'll want to keep the intake about 5" off the bottom to prevent sand from getting sucked up......this will make for a noisy filter and eventually will kill the impeller.
When refilling the tank during w/c, use a large plate to deflect the water to prevent disturbing the sand too much. Every month or 2, stir up the sand, to prevent anaerobic conditions