Swimming pool leaks happen even in well-maintained pools. They can be a result of normal deterioration or even from the ground around your swimming pool shifting. Leaks can be tricky to identify and fix. But with some expert tips, savvy pool owners can often take care of pool leak repair themselves.

How to Determine if Your Pool Is Really Leaking

Before you get ahead of yourself trying to find a leak in your pool, let’s make sure that it is actually leaking. Swimming pools can lose a surprising amount of water from evaporation, especially when there is a lot of exposure to direct sunlight, very high temperatures, or low humidity. In fact, under the right conditions, a pool can lose up to two inches of water per week just through evaporation! If you have had your pool for a while, you probably know how much water loss is normal, as it varies widely from pool to pool. If you are unsure if it’s a leak or just normal evaporation, the bucket test is a simple way to find out!

Perform the Bucket Test

The Bucket Test is a nifty little leak detection trick that we use in the pool industry to compare the evaporation rate of the water in the pool to the water in a bucket.

  1. Fill a 5-gallon bucket to within an inch or two from the top with water from your pool. You must use pool water so that you are comparing apples to apples.
  2. Position the bucket on your pool steps so that the water level in the bucket is even with the pool’s water level.
  3. Mark the waterline in the bucket and the pool with some masking tape.
  4. Wait 24 hours and check the levels. If the water has decreased by the same amount in both the pool and the bucket, do a happy dance, because your pool is not leaking! If the water level in the pool has decreased by more than the bucket, your pool is probably leaking.
  5. If you have decided that you do have a leak, you can repeat the test with the pool pump turned off to help determine where it is.
    • If you lose less water when the pump is off, your leak is probably in the skimmer or main drain.
    • If you lose more water when the pump is off, the leak is most likely in the return lines.
    • If the water loss stays the same with the pump off, the leak is probably in the fittings, liner, or pool shell.

How to Find a Pool Leak

Unfortunately, you have determined that the water loss in your pool is more than just evaporation, and now you need to find the leak. Thanks to another nifty pool industry trick called the Dye Test, you might be able to DIY it. You can use any type of dye that you have at home, including food coloring.

  1. Choose a day that is not very windy, and turn off the pool equipment.
  2. You may need to get in the pool with some goggles and even a snorkel if you have one. Move slowly in the water so that you don’t disturb it too much.
  3. Release a burst of dye near the suspected leak. If there are visible cracks, those are a great place to start, if not, you can start around the skimmers or return lines.
  4. If the dye gets sucked into the crack, you have likely found the source of your leak.

If you still can’t find your leak with the dye test, it’s probably time to call a local pool repair shop or a pool leak detection professional. They can use specialized equipment to check the pipes or to perform a pressure test and find the source of the leak.

How to Fix a Pool Leak

Swimming pools have a lot of moving parts, and some types of leaks are easier to fix than others. Types of leaks that are pretty simple to fix include:

Liner Leaks

If your above ground pool or inground pool has a vinyl liner, Doheny’s Vinyl Liner Repair Kit is easy to use and can even be applied underwater. Just follow the instructions on the patch kit to cut the vinyl patch to the correct size and place it over the damaged area. Vinyl pool liner leaks are one of the easiest fixes!

Skimmer Leaks

Pool skimmer leaks can occur over time in concrete pools when the natural shifting and settling of the ground causes the seal between the pool wall and the skimmer to be broken. Repair skimmer leaks using pool putty. Simply use your fingers to knead the putty into the broken seam or crack and smooth it out. Wait at least 24 hours for it to cure before turning on your pool pump.

Tile Leaks

Leaks caused by cracks in the pool tile or grout are a common problem and can be fixed by applying pool putty, epoxy, or a rubber-based sealant directly to the crack. Be sure to follow the manufacturer’s directions for application.

Plumbing Leaks

A pool plumbing leak can be trickier to deal with, especially if it is in your underground plumbing. For small leaks, try Lo-Chlor Leak Sealer, an easy-to-use chemical that works on most minor pool and hot tub leaks by “clotting” at the spot of the leak. Follow the manufacturer’s directions to add it to your pool water and circulate, making sure to bypass your pool filter as it will cause clogs. Lo-Chlor Leak Sealer cannot be used in vinyl-lined pools. For more extensive underground plumbing leaks, or other types of pool leaks, we recommend calling a pool repair professional who will be able to quickly find the exact location and repair the problem.

While pool leaks are a headache to fix, it is important that they be taken care of in order to protect your pool equipment and avoid wasting expensive chemicals and water. Some types of leaks can be prevented with good pool maintenance while others are inevitable. If you have questions about fixing a leak in your swimming pool or hot tub, call Doheny's pool professionals at 800-574-7665 or visit our website at doheny.com.