i had the same problem as you with the tank not fully contacting with the stand.. i went out and got a 8'x2' piece of 1" foam and it solved the problem. i had some left so i also cut some for the bottom of my canister filters as you could here a slight vibration. i solved that also with the foam...if you have some left, i would also do the sump, just to be safe. i never used styrofoam under any of my tanks, but i will for now on.