How to Find and Fix Pool Leaks

Steps for finding leaks in your pool and how to repair them.

Water disappearing from your pool basin could be regular evaporation - or something far more serious. If it's leaking, where's the leak, and what can you do about it? Read on:

In cases in which a leak is highly suspected, simply shut off the circulation system and keep an eye on the water level.

Slow leaks can be confirmed by filling the pool to its normal level, filling a plastic bucket with water and marking the water level on both the pool and the bucket.

After 24 hours, compare the levels in the bucket and the pool. If the pool loss is greater than the bucket loss, you have a leak.

If the water is disappearing at a fast rate, finding the water flow out of the basin is sometimes as simple as donning a snorkel mask and injecting grape juice or watercolor paints at various points along the pool basin and watching where it goes.

For leakage that doesn't appear to be occurring in the shell itself, try the "pump on/pump off" test.

With the pump on, measure the amount of water lost over a 24-hour period. Then do the same with the pump off and compare the results. If there is no difference in the amount of water lost with the pump either on or off, the leak may be in the pool shell. If the amount of water lost with the pump on is greater than the loss with the pump off, the leak is likely on the pressure side of the plumbing. If the water loss with the pump on is less than the loss with the pump off, the culprit may be a suction-side plumbing leak.

Many structural leaks can be plugged with an underwater curing epoxy that is the color of plaster.

Simply smear it over the crack with a spatula, smooth it with underwater sandpaper and allow it to cure.

If the leak is caused more by a tiny hole than a crack, an underwater patch seal works if formed into a ball and jammed into the damaged area.

For leaks in the plumbing or in pool decks built over an open space below (such as a locker facility, filter room or storage area), hire a specialist.

Serious cracks can leave a white residue on the ceiling of the area below the deck, caused by leaching chloride, which in turn damages the structural rebar.