Swimming Pool Leak Detection

Leak Detection: Telltale Clues
One or more of these clues might indicate your swimming pool or spa is leaking:
1.    Persistant water-quality issues or algaes that indicate imbalances in the water chemistry, because     a leak prevents constant, even levels.
2.    Loose tiles or cracks in the pool deck or surrounding area.
3.    Loose coping stones.
4.    Tree roots can lift the pool deck, plumbing or pool walls.
5.    Cracks or gaps in the bond beam.
6.    Soggy soil near the pool, spa, pumps or pool plumbing equipment.

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.
No. 2: The Dye Test
1.   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.
2.   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.
3.   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
4.   Observe: Continue checking other areas, like fittings, lights, skimmer, main drain and return outlets.
Leak Detectors & Pressure Testing: Summon the Pros
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.