You don't really need the styro IF the tank is well supported by a proper stand and is level. But yes most stands you buy are made only to support the outter edges of the tank, some of the larger tanks will also have cross bars to support some of the centers. If you are looking for the styro for added protection you can go to HD and pick up a sheet of the stuff, its the same stuff they put on the basement walls on the outside. Just trim to fit.