How to fix a Leaking Fish Tank

A leaky aquarium tank can be a big problem. Most leaks only spill a little water at a time. If this problem isn't fixed, it can lead to the whole aquarium breaking or wasting a lot of water.

Difficulty: Moderate

Instructions

Things You'll Need:

• Razor blade or razor scraper.
• Acetone.
• Sealant.
• Temporary container or aquarium if you must empty the one you are repairing.

1. Identify where the leak is.
   
   * Look around the aquarium for wetness, if the leak is not obvious.
   * Look for metal corners that appear to be serperated from the glass, and for sealant protruding in the corners.
   * Feel around the edges, and if you feel water, move upward from that location, until the surface feels dry.
   * Mark the location of the leak, or where you suspect the leak is, with a felt tip pen.

2. Drain the water low enough to allow room to clean and dry the area around the leak. If the leak is very low in the tank, you may have to remove the fish and aquatic plants to a temporary container or other aquarium while repairs are made. Remember that the sealant you seal the leak with will have to cure before refilling the tank, so plan accordingly to keep your fish and plants healthy.

3. Scrape the old sealant around the leaking area with a razor scraper. If you are sealing the tank from the inside, be careful not to allow any of the old sealant to drop in the tank.

4. Wipe the area with a clean cloth dampened with acetone to remove any residue and other foreign material. Dry with a paper towel, and allow to completely air dry, about 15 minutes.

5. Apply nontoxic 100% silicone sealant to the leak area. Allow the sealant to dry and cure a minimum of 12 hours, but preferably 24 hours.

6. Refill the tank and inspect for leaks. If you have removed fish and plants from the tank, replace them when you are confident the leak is repaired.

Tips & Warnings

• You may try to repair the leak from the outside of the tank, but usually the repair is more effective if made on the inside, since water pressure will "tighten" the seal pressing the silicone out, against the glass, but pushes it away from the glass when applied from the outside.
• Check with a professional aquarium supply for recommended repair products. Make sure that if you use silicone, it is labeled "nontoxic" and "100% silicone".
• You may use a heat lamp or other portable heat source to help cure the sealant, but do not heat above 110 degrees (F).
• Very large aquariums have more water, hence more pressure on the seams, and can be very difficult to repair.
• Never use solvent based glues on aquariums.
• Do not attempt to move an aquarium which is filled with water, the movement may cause the seams to distort and the aquarium to leak or burst.