Methods for Resealing an Aquarium

In general, when done properly, aquarium sealing should last about 20 years. If your aquarium is cracked or leaking, it may be time to reseal your aquarium. Many people will mistakenly assume that once the sealant around their tank begins to show signs of wear and deterioration, they must replace the entire tank. This is much more expensive than repairing your aquarium and is unnecessary. Resealing is a relatively simple process that you can easily do by yourself at home, making your tank as good as new.

  1. Resealing Glass Aquarium Leaks

    • Room temperature vulcanized, or RTV, silicone is ideal for resealing glass aquariums. Use a product that is 100-percent silicone, or you may inadvertently poison or harm the fish in the tank. Before you can beginning the sealing process, you will need to empty out your tank. Remove all of the old silicone from the tank using a razor blade or craft knife. Dry out the tank, then replace the sealant using a caulking gun. Use your index finger to smooth the silicone as you work.

    Glass Aquarium Chips

    • A chip in your aquarium can cause significant leaks or spills. Chips also can be hazardous due to the sharp edges that may have resulted. Generally, chips in aquariums will occur around the corners of the tank. Begin by draining the aquarium down to the spot of the chip. Carefully inspect the aquarium for any broken glass. Take another piece of glass that is about the size and shape of the chip, and use a 100-percent silicone product to seal the glass in place.

    Large Aquarium Cracks

    • For small cracks in your aquarium, you can simple add the silicone sealant and allow it to dry. For larger cracks, add another pane of glass to the inside of the crack before adding the silicone sealant. If your tank is over 10 gallons, even if there is only a minor crack, you should have the added support of another pane of glass when resealing.

    Acrylic or Plexiglass Aquariums

    • Silicone cannot be used to repair acrylic of plexiglass aquariums, as the silicone will only properly attach and seal itself to a glass surface. If you have an acrylic or plexiglass aquarium, you will need to seal your tank using a plexiglass or PVC cement glue. A needle applicator is often a useful tool for performing this type of resealing. Apply the plexiglass or PVC cement glue following the same steps as you would when resealing a glass tank with silicone. After applying the glue, you can add a layer of silicone sealant for an extra tight water resistant seal, but the silicone does not provide any extra support for the acrylic or plexiglass.