How to Clean a Used Fish Tank

Finding a fish tank at a garage sale can be a joyful event for fish enthusiasts, since fish tanks are usually expensive when purchased new from a store. The drawback of buying a used tank, however, is that you cannot be sure of its true condition until you take it home and test it for leaks. The tank also must be cleaned, since you cannot know how long the previous owner stored it in the garage or what the tank was used for.

Things You'll Need

  • Water
  • Paper towel
  • Silicone sealant
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Instructions

  1. Test the Tank for Leaks

    • 1

      Place the tank on surface that is flat and level. If the tank is small, a bathtub may be ideal.

    • 2

      Pour water into the tank until it is about one-quarter full, then wipe any moisture off the outer walls of the tank. Let the tank sit undisturbed for 24 hours, then check it for leaks.

    • 3

      Repeat Step 2 to test for leaks at different levels of the tank. Check the tank when it is half-full, ¾-full and completely full.

    • 4

      Repair leaks. If there are leaks in the fish tank, you must repair them before you can use it for fish. Apply a silicone sealer along the joints in the tank to plug any holes along the joints. You can purchase a tube of silicone sealant from a hardware store or from the hardware section of a retail store. Ensure that the sealant is safe for fish tanks. If the tank cannot be repaired with sealant, then it must be replaced.

    Clean the Tank

    • 5

      Rinse the tank thoroughly with cold, running water. According to information on Firsttankguide.net, any debris or deposits on the walls of the tank would have loosened in the standing water during the process of checking for leaks and you can rinse them off. If there are any stubborn stains, try scrubbing them off with a paper towel. Aquahobby.com recommends scraping off calcium deposits and crusted algae with a razor blade.

    • 6

      Pour the water out of the tank. Wipe the walls dry with a paper towel.

    • 7

      Consider replacing items that came with the tank. If the tank has not been used in months, it is best to replace the filter. Also consider replacing the gravel, since it has highly porous surfaces that are difficult to sterilize.