Swimming Pool Leak Detection
Every pool loses some water. In a UK summer an outdoor pool can lose several millimetres a day to evaporation alone, more with wind, heating and heavy use. The question is whether your pool is losing more than that, and if it is, whether the water is going through the shell, the liner, a fitting or the buried pipework. Each has a very different fix, which is why finding the leak properly matters more than guessing.
First, prove the leak
The classic bucket test separates evaporation from leakage: a bucket of pool water on the top step loses water to evaporation at the same rate as the pool, so if the pool level drops faster than the bucket, water is escaping. We take it further with timed level measurements with the circulation running and then off, because the difference between the two immediately points at either the pipework or the shell.
Where pool leaks hide
- Circulation pipework: skimmer, return and main drain lines buried in the surround. Isolated and pressure tested line by line, then pinpointed with tracer gas or acoustics exactly as we would a buried water main.
- Fittings and penetrations: skimmer throats, return eyeballs, lights and stanchion sockets, checked with dye testing at the fitting.
- Liners: punctures and failed seams, found by methodical dye testing. A liner leak does not mean a new liner if the hole can be found and patched.
- Concrete and tiled shells: cracks and failed grout lines, dye tested and mapped so the repair is targeted.
No need to drain down
Almost all of this is done with the pool full. Draining a pool for investigation is not just wasted water and heat: an empty shell can be damaged by ground water pressure, and liners shrink. If a drain-down is ever genuinely required, it comes after the leak is located, not as a way of looking for it.
Spas, hot tubs and plant rooms
The same methods scale down to spas, hot tubs, and the plant room itself: pumps, filters, valves and heat exchangers are checked as part of every pool survey, because a surprising number of pool leaks turn out to be a weeping joint two metres from the pump.