Resealing a Leaking Aquarium

A leaking fish aquarium can be a nuisance, but the process of resealing one isn't difficult or complicated, although it can be time consuming. It takes at least 48 hours to see the process through, from the first step of draining of the tank to waiting for the sealant to dry before testing it.

  1. Drain the Aquarium

    • If the exact location of the leak isn't known, it has to be found first. To do this, the aquarium should be drained, then dried out. Then it has to be placed on a flat surface with pages from a magazine or newspaper underneath it. It should then be refilled with water until a spot of water dampens the paper underneath. At this point, the refilling process should stop and the point of the leak found. The leak will be distinguished by a marked difference in the way the sealant looks compared with the rest of the tank.

    Remove the Sealant

    • Mark the leak's location with tape, then drain the aquarium a second time. Using a razor blade, X-Acto knife, or similar tool with a blade, cut out the sealant where the leak is, as well as a few additional inches of silicone along both sides of the leak. Peel to remove the bad patch of sealant from the aquarium, then scrape off any specks of silicone.

    Wipe Down the Area

    • After the removal of the sealant, use vinegar or another acidic agent that won't leave any harmful residue on the glass, to wipe down the exposed area of the aquarium. For this process, the aquarium should be either outdoors or in an area with good ventilation, like an open garage, because the odor from the chemicals can be strong.

    Apply Silicone

    • Apply silicone sealant along the leaking area, and wet one finger and use it to smooth out the silicone. Then wait at least two days for the aquarium to dry before refilling and using it again. Wash your hands soon after the sealant is applied, so that the silicone doesn't dry on your skin. If your finger that was used to apply the silicone still contains traces of the sealant after the hand washing, use nail polish remover or another organic solvent to clean the hand area.