Aquarium silicone sealant is a silicon and oxygen water-resistant glue that can adhere to most surfaces, especially glass. This clear and flexible material is highly resistant to changes in pressure and other environmental conditions, including weather, sunlight, and temperature. Silicone is applied as a liquidy gel but gradually cures as a secure tacky putty.
For smaller tanks, it usually takes 24 hours for the silicone to cure. For larger tanks, it's best to give as much time as possible for curing to make sure that there are no unfinished areas. The curing process must take place outside of the water and be exposed to oxygen. It is best to perform a watertight test after the curing to make sure that no areas of the tank are lacking aquarium silicone sealant.
How to Apply Aquarium Safe Silicone Sealant?
Before starting the repair, we recommend you check all the seams for secureness. If you drain the tank for one leak, it's smart to check the integrity of the other seals while you're at it.
Remove water to a point well below the line you're fixing. We recommend you remove the fish and completely drain and clean the tank.
Remove the old sealant with a straight razor or another sharp tool. If your fish are still in the tank, avoid dropping silicone residue in the water. Don't pull the silicone bead away unless you're replacing the entire seam.
Clean the joints to remove old stubborn residue from the glass. Consider using mineral spirits to completely remove any residue.
Starting on the inside of the tank, apply your aquarium safe silicone sealant bead into the seam along the joint. Take care to fill any gaps with the sealant.
Repeat application on the outside of the tank, make sure you don't have gaps in the aquarium safe silicone sealant.
Wait for cure time to be achieved before refilling the tank with water.
Fill the tank slowly, while making sure your seam is secure.