Glass panels are used to build glass aquariums, and a silicone-based asi aquarium silicone sealant holds them all together. The sealant maintains the connection between the glass panels and creates a waterproof seal. Occasionally a new aquarium will leak as soon as you fill it up if the factory seal is not fitted properly. Aging aquariums that have been moved around a lot are also susceptible to seal leaks. If that occurs to you, try not to be alarmed. A silicone sealer can be used to fix a leak at home.