Leak Detection Guide
Place a bucket on a pool step so it's partially submerged, then fill it with water to match the pool's current water level, marking both levels clearly. Turn off the pool's auto-fill if it has one, then wait 24 hours. If the pool's water level has dropped noticeably more than the level inside the bucket, the difference is likely a leak rather than evaporation, since both are exposed to the same weather conditions.
Pools typically lose about a quarter to half an inch of water per day to evaporation under normal conditions, more in hot, dry, or windy weather, and less in cooler or humid conditions. Knowing this baseline helps you judge whether your pool's water loss is within a normal range or something more.
Water loss that continues even when the pool isn't being used, cracks or stains on the pool shell, air bubbles coming from return jets, or a consistently soggy area of ground near the pool equipment pad all point toward an actual leak rather than evaporation.
Pool leaks most often occur at the shell itself (cracks or gaps in plaster or vinyl liners), in the underground plumbing lines running to and from the pool, or at fittings and equipment connections at the pad. Each location requires a different detection approach, from dye testing at suspected shell cracks to pressure testing the plumbing lines.
The skimmer is one of the most common leak points, since it's a cutout in the pool shell and the seal around it can degrade over time. Equipment pad leaks — at pumps, filters, or heater connections — are often visible as damp ground or active dripping, making them somewhat easier to spot than shell or underground plumbing leaks.
If the bucket test confirms water loss beyond normal evaporation but you can't visually locate the source, that's the point for professional detection — dye testing, pressure testing, and sometimes dive inspection can pinpoint leaks that aren't visible from the surface.
