How to Repair Silicone for an Aquarium

Most aquariums are sealed with silicone spread over the edges of the glass where the panes meet. Over time, this silicone may shrivel, chip, loosen, or wear away. When this occurs, the tank will leak. Fortunately, there is a way to repair and replace the silicone, so you do not have to replace the entire tank. Within 24 hours, your tank will be as good as new.

Things You'll Need

  • Razor
  • 100 percent silicone sealant
  • Caulking gun
  • Vice grip
  • Towels
  • Screwdriver
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Instructions

    • 1

      Empty the tank of all fish, plants, water and equipment. Dry the tank with old towels. Lay the tank on its side, with the side that needs to be sealed facing you. If you have to repair more than one side of the tank, choose one side to work with first. Repair only one seal at a time, so the tank is held together the entire time.

    • 2

      Tighten the vice grip over the razor blade. This holds the razor firmly in place, and gives you a little more room to work with the razor. This also helps prevent injuries, because the blade is farther away from your hand.

    • 3

      Cut the old silicone straight down the middle, between where the two panes of glass meet. If necessary, cut halfway through on one side, then cut the other half from the other side of the tank.

    • 4

      Cut out the corner of the silicone by angling the razor blade where the silicone and glass meet along the corners. Cut straight down one side of the silicone, all the way to the next pane of glass. Repeat for the other side. Use a screwdriver to lift the edge of the silicone.

    • 5

      Pull gently on the silicone strip to remove it from the tank in two long pieces. If you run into any trouble spots, free the stuck piece with the razor blade. Scrape away any residual silicone with the flat edge of the blade.

    • 6

      Place the silicone sealer inside the caulk gun. Spread an even bead along the edge where the two panes of glass meet. Try not to clump the silicone.

    • 7

      Dip your finger in a cup of water, then run your finger along the top surface of the silicone to smooth it. This helps the silicone bond with the entire surface of glass. Allow to dry for 24 hours.

    • 8

      Test the seals by filling the tank with water. If that seal still leaks, remove the silicone and start over.