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Leak or evaporation? How to tell in a heat wave

Pools lose water fast in valley heat. The bucket test tells you whether that is normal or a leak worth fixing.

Updated September 24, 2026 · Johnny's Pool & Spa Service · Repair & equipment →

In a San Gabriel Valley heat wave, a pool can lose a noticeable amount of water to evaporation in a single day. Wind makes it worse. That is normal. A leak is different, and the sooner it is found the less it costs.

The bucket test

Fill a bucket with pool water and set it on the first or second step so the water levels inside and outside match. Mark both levels. Turn off the auto-fill if you have one. Compare after 24 hours. If the pool dropped more than the bucket, you are losing water somewhere other than the air.

Run it twice

Do the test once with the pump running and once with it off. If the loss is worse with the pump running, look at the pressure side: plumbing after the pump and the equipment pad. Worse with the pump off points to the suction side, the skimmer, or the shell.

Signs to watch

Wet spots in the yard, a pump that loses prime, air bubbles from the returns, cracks around the skimmer, and a water bill that jumps are all worth mentioning to us.

Finding and fixing it

Our repair staff finds and fixes plumbing, light niche, skimmer, and shell leaks. Every repair is quoted before it starts.

Get a quote (626) 966-8684