How to Reseal an Aquarium

Over time, the sealant that keeps your fish tank water tight may wear out and you could find yourself with a leaky aquarium. In cases like this the aquarium may be due for a repair job or a resealing process. This is especially useful if you have purchased an old or damaged aquarium. Try a few resealing and repair techniques rather than putting up the cost for a brand new tank. Whatever your reasons for resealing an aquarium, use care to make sure the aquarium is water tight.

Things You'll Need

  • Glass aquarium
  • Paper towels
  • Rubbing alcohol
  • Cotton swab
  • Razor blade or utility knife
  • Tube of silicone aquarium sealant
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Instructions

    • 1

      Empty the aquarium of water and dry it completely with absorbent paper towels. Set the aquarium on a table or flat surface where you can easily reach into and around it.

    • 2

      Scrape away the old silicone from inside the corners and bottom of the tank using a razor blade or utility knife. Be careful not to scratch the glass. Dispose of the old silicone when you are finished.

    • 3

      Wipe down the surfaces of the tank with rubbing alcohol and a paper towel or cotton swap. Pay particular attention to the corners of the tank and feel for any bits of silicone that you may have missed. Scrape away any leftover silicone with a razor blade and clean the tank thoroughly with the alcohol, then let it dry.

    • 4

      Fill a small container with rubbing alcohol and place it inside the tank. Coat your fingers with the alcohol before spreading the silicone so it does not stick to your fingers.

    • 5

      Cut the tip off the silicone tube with your razor blade or utility knife and apply a generous bead of silicone all the way down one edge of the tank. Quickly dip your fingers into the rubbing alcohol then use them to spread the silicone into the cracks and corners and to smooth away any air bubbles. Wipe your fingers on a paper towel before moving on.

    • 6

      Finish the other sides of the aquarium in the same manner by applying the silicone and spreading it with your fingers. Pay extra attention to the corners, being sure to press the silicone as far into the corners of the tank as possible to prevent leaks.

    • 7

      Allow the silicone to dry for 24 hours then examine the tank. If you see any areas where the silicone is layered too thin add another coat and allow it to dry for another 24 hours.

    • 8

      Allow the silicone to cure for a full 48 hours before going back and cleaning up your work. Scrape away any spills with rubbing alcohol and a razor blade.

    • 9

      Rinse the tank well to remove any traces of rubbing alcohol then fill it to test it for water tightness. If the tank does not leak after being full for 24 hours it is considered safe to use.