Aqueon Glass Aquariums Tempered vs. Non Tempered: Due to glass availability, Central Aquatics may temporarily substitute regular or non-tempered glass panels with tempered glass panels. Anytime a glass substitution is made, a sticker will be adhered to the aquarium bottom as a precaution to the end user. Please Note: Any aquarium that is altered in any way (i.e. - drilled, attempted to be drilled, the center brace removed) by an individual outside of Central Aquatics, will deem the warranty null and void.