yeah tanks like juwel's, rena's etc have what's called a floating base and don't require polystyrene or anything else inbetween, check the manufacturers instructions. but for a regular glass aquarium (especially a 6'x2'x2') you should have something between the glass and the stand, doesn't have to be polysytrene it's just what's normally used as it's cheap and easy to get hold of.
