Many aquarium keepers are starting to place foam pads under their tanks when setting them on the stand these days, with the presumption that the foam will provide a sort of leveling cushion that fills in any gaps caused by imperfections in the stand. While the presumption is true to some extent, the presence of foam can present a potentially dangerous hazard for one particular type of tank. Rimless aquariums benefit greatly from the added foam, but it can be a great detriment to those tanks with the plastic trim pieces and will likely void the warranty if used. For those trimmed out tanks, the glass sits up off the stand altogether. The tank itself rests on the plastic trim, and any foam padding would put uneven pressure on the glass bottom of the aquarium. The uneven pressure could results in a small hairline crack or a massive tank failure.