Signs that a swimming pool or hot tub is leaking may or may not be obvious. If you suspect a leak, there are proven ways to inspect and detect. In the tome, The Ultimate Guide to Pool Maintenance, author Terry Tamminen suggests several methods for detecting leaks in pools and spas. Some he considers easy do-it-yourself methods, others he suggests consulting a professional.
Give your chosen test some time, care, and patience. Oh—and prepare to get wet.
9 Signs Your Pool is Leaking
One or more of these clues might indicate your swimming pool or spa is leaking:
- Persistent water-quality issues or algae that indicate imbalances in the water chemistry, because a leak prevents constant, even levels.
- Loose tiles or cracks in the pool deck or surrounding area.
- Loose coping stones.
- Tree roots can lift the pool deck, plumbing or pool walls.
- Cracks or gaps in the bond beam.
- Soggy soil or grass near the pool, spa, pumps or pool plumbing equipment.
- Your pool deck is sinking or lifting.
- You need to add water to the pool more than once a week.
- Your pool or spa seems to be losing about 1/4-inch of water each day.
Leak Detection Test No. 1: The Evaporation Test
In the evaporation test, author Tamminen suggests filling a bucket and placing it on the deck next to the pool or spa. With an indelible pen, mark the level in the bucket and also for the pool or spa. Turn off the circulation. Wait a few days, then mark the new level in the bucket and pool or spa. Both the bucket and pool water should evaporate equally (using inches or centimeters). If the pool or spa level is significantly more, you may have yourself a leak. If the water levels evaporate at the same rate, then it is probably not a leak.
Leak Detection Test No. 2: The Dye Test
- Prep: Carefully clean and brush the pool, paying attention to steps, corners, and fittings. Begin your inspection on a calm day, since wind ripping the surface makes it hard to see small cracks. Squirt tile soap across the surface to increase visibility.
- Inspect: Examine for cracks, starting at the tile line. Tap the tiles gently with a tool to see if any fall off, are loose or sound hollow.
- Dye Time: Squirt a squeeze bottle with food dye in areas of suspected leaks. Enter the pool. Squeeze dye. If it swirls around the crack without getting sucked in, no leak. If the dye gets sucked in, it's riding on a flow of water leaking from the pool
- Observe: Continue checking other areas, like fittings, lights, skimmer, main drain, and return outlets.
When to Call a Professional
If the other methods fail to help you locate a suspected leak, there are two other methods of leak detection. Unless you're a plumber, happen to own a geophone or an extreme DIYer, call on the pros.
By applying the geophone—an electronic listening device—an operator can actually hear water dripping or flowing. By using the device around a pool and related plumbing, the operator can identify where water is moving out of the system.
Method No. 2 is leak detection via pressure testing equipment. Again, it takes know-how and additional equipment to conduct a pressure test. Your wisest move is to hire a pool builder, plumbing contractor or leak detection company that has the right stuff to do the job.
Schedule a Professional Leak Detection Test
If all tests indicate your pool has a leak, contact a reputable leak detection service to conduct a test. To make sure you get an accurate leak detection test, vacuum and clean the pool vacuumed and beforehand. Dirt and debris in the pool can make it challenging to spot even large leaks. Water should be as clear and clean as possible. If it is green it most likely means your pool has mildew, algae, or fungi.