Every summer, homeowners across the Triad watch the water line drop and assume the worst. Sometimes they are right. Often they are watching normal evaporation in July heat. There is a free test that settles it in 24 hours, and it is worth running before you spend money on anything.
How much loss is normal
A pool loses water to evaporation continuously, and the rate goes up with heat, low humidity, wind and sun exposure. It also goes up with water features running, because a waterfall or deck jets massively increase the surface area exposed to air. A heated pool evaporates faster than an unheated one, and an uncovered pool evaporates far faster than a covered one.
Splash-out from active swimming and backwashing also remove water, and both get counted as leaks by people who did not think about them.
The practical point is that some daily loss in a Piedmont July is expected. Meaningful loss that continues in cool, still, cloudy weather is not.
The bucket test
This is the standard method and it works.
- Fill a bucket with pool water and set it on a pool step so it is partly submerged, which keeps its water at the same temperature as the pool.
- Mark the water level inside the bucket and the pool level outside it.
- Leave the pool running as it normally does. Do not add water, do not swim, do not backwash.
- After 24 hours, compare. If both dropped about the same amount, that is evaporation. If the pool dropped noticeably more than the bucket, you have a leak.
Run it again with the pump off for 24 hours. If the loss is much worse with the pump running, the leak is likely on the pressure side of the plumbing. If it is worse with the pump off, suspect the suction side or the shell.
Where leaks usually are
The equipment pad. Always look here first, because it is free to check and it is a common answer. Look for wet ground, drips at unions, a weeping pump seal, or a leaking filter o-ring. Many suspected pool leaks turn out to be a fitting at the pad.
Skimmers. The joint between the skimmer body and the pool wall is a frequent failure point, particularly on older pools and in freeze-thaw climates like ours.
Return fittings and lights. The seals around returns and light niches are common leak points.
Plumbing underground. Harder to find and usually indicated by wet or unusually green areas in the yard, or by a pool that loses water only when the pump runs.
The shell. Cracks in gunite, tears in a vinyl liner, or separation at fittings. Piedmont red clay is expansive and our freeze-thaw cycles do work on structures over years.
Autofill devices. A stuck autofill masks a leak entirely, since the pool never appears to drop while the water bill climbs. Check yours.
Narrowing it down
Let the water find its own level with the pump off, and note where it stops. If it stops at the skimmer, the leak is at or near the skimmer. If it stops at a return, look there. If it keeps dropping past all fittings, suspect the main drain or the shell.
Do not leave a pool substantially drained while investigating. A vinyl liner pool can float its liner, and any pool in saturated Piedmont clay can be affected by hydrostatic pressure. Draining a pool is not a casual step and should be discussed with a professional first.
Why finding it matters beyond the water bill
A persistent leak does more than waste water. It continuously washes away chemicals so the chemistry never holds. It can undermine soil beneath decking, which shows up as settled or cracked concrete. And on a sloped Piedmont lot, sustained water in the wrong place is a real drainage and structural concern.
When to bring in leak detection
If the bucket test confirms a leak and a walk of the equipment pad does not reveal it, professional detection is the efficient path. Pressure testing the plumbing lines, dye testing at fittings and suspected cracks, and listening equipment locate leaks without digging up a yard on guesswork.
The cost of detection is almost always smaller than the cost of excavating in the wrong place.
Reducing evaporation
If the answer turns out to be evaporation and you want less of it, a pool cover is the single most effective measure and it also holds heat, which extends the swim season here. Running water features less on hot windy days helps. And windbreak planting or fencing reduces the wind exposure that drives evaporation on open Piedmont lots.
We handle leak detection and repair on existing pools across High Point, Greensboro, Winston-Salem and the surrounding Triad. Reach out or call Oasis Pools at (336) 471-0103.