Evaporation in the Pool: Normal Water Loss or a Leak?

A falling water level does not necessarily mean a leak. Heat, dry air, wind, and swimming cause water to evaporate or splash out. The important thing is to measure the change under comparable conditions.

Short answer: Mark the water level, track it for 24 hours without topping up, and compare the pool with a bucket standing in the same climate. A clearly larger drop in the pool may indicate a leak.

What affects evaporation?

A large temperature difference between the water and the air, low humidity, and wind increase evaporation. Warm pool water and an unprotected water surface can therefore cause noticeable level loss without anything being broken.

Swimming, play, backwashing, and cleaning can also remove water in other ways. Note such events when you measure.

Do a simple bucket test

If the levels drop about the same amount, that points to evaporation. If the pool drops noticeably more, you need to continue troubleshooting.

Signs that should be checked

• The water level also drops in cool, calm weather
• The ground is unusually damp near the pool or equipment room
• The pump is drawing in air or the water level falls to the same point
• You need to top up much more often than before

Reduce unnecessary water loss

Use a suitable pool cover when the pool is not in use, check the backwashing routine, and fix drips at connections. At the same time, keep the correct level for the skimmer and pump; too low a level can damage circulation.

Frequently asked questions

How much evaporation is normal?

It varies greatly with weather, water temperature, wind, and protection. A local measurement over several days gives a better answer than a general figure.

Can I repair a suspected leak myself?

Visible drips at simple connections can sometimes be fixed, but hidden leaks and work on the pool structure should be diagnosed professionally.

A suitable pool cover can reduce both evaporation and heat loss.