How to Fix a Leaky Aquarium

It turns out that aquarium leaks are pretty easy to fix, even ones that look pretty severe. As long as the glass panels are not cracked or badly chipped, you can do it yourself and fix the largest aquariums for well under $10. The real cost is going to be measured in time. It is best if you can empty the entire tank, but you might not have that luxry. All in all, the whole process is pretty easy. In fact, if you have ever re-caulked your bathroom tile, fixing an aquarium leak should be a snap.

I happened to be perusing a local second hand store, called Deseret Industries, and I found a 65 gallon aquarium for only $7.00. It was pretty dirty, but there were no cracks and it seemed to be in pretty good shape. I could take it home, clean it up, then advertise it on Craigslist. Even if it had leaks, I could sell it to someone who kept reptiles and still make a killing. All in all it was a safe deal.

The first thing I needed to find out was whether or not it leaked. I put it on the floor of my garage and filled it with the garden hose. I soon found out why someone had gotten rid of it. The leak was pretty severe, and in no time at all I had a major flood in my garage. I felt really sorry for the previous owners. 65 gallons can cause an extensive amount of water damage. I had quite a challenge ahead of me.

You will need the following items:

• A tube of silicone sealant. Use only non-toxic, 100% silicone, clear sealant.
• A razor blade scraper

The sealant is the most important part. It should cost you between $3.00 and $5.00. Not a bad investment, all things considered.

Some other things you might need:

• Acetone (nail polish remover) for cleaning the area around the leaky spot
• Paper towels
• Felt tip marker (to mark the leaky spot)

REMEMBER: This job will take some time. You aren’t going to fix an aquarium leak in 10 minutes.

Some things to consider:

• The patch will work best if you fix the leak from the inside of the aquarium.
• The patch will be the strongest if you re-seal both the inside and the outside.
• The patch will look best if you re-seal the whole edge where the leak was found—not just the immediate area of the leak.

You can try to do this with your fish still in the tank, but it will be best if you can safely move your fish somewhere else. All of the chemicals used in this process are toxic until they have dried up or cured. Go down to Target and get a large plastic bin. You can hang your filter and heater from the side and your fish can live there happily for several days.

Preparation:

1. (optional) mark the spot where the water is leaking with a marker or a grease pencil.
2. Drain the aquarium completely and empty it out.
3. Clean the area around the leak. Make sure there is no algae, or lime deposits, or salt creep. Use a sponge to get the area wet, then scrape it clean with a razor blade.
4. Make sure the spot you are going to seal is completely dry. Wipe the spot off with a towel and then let it sit for an hour or two.
5. Using the razor blade, cut the silicone away from the leaky area. Cut away an additional one or two inches beyond the leaky area.
6. Clean away any grit or grime that had accumulated underneath the old sealant.
7. (optional) Cleanse the area with a bit of acetone applied to a paper towel.

Apply the sealant:

1. (optional) If you want the new seal to have a nice, even edge, you can apply a strip of masking tape along both sides of the area.
2. Apply an even bead of silicone sealant to the area, a little less than 1/4 inch wide. Make sure the sealant gets forced into the crack between the two pieces of glass.
3. Using your finger or a tool, smooth the bead over to give it a nice rounded shape. This also forces some of the sealant into the crack.
4. Strip away the masking tape immediately after you are done.
5. Let the sealant dry for 24 hours.

Testing the seal

1. Fill the tank up completely.
2. Let it stand for another 24 hours.