Symptoms
- Water level drops noticeably day to day
- Wet spots in the yard near the pool equipment or shell
- Air bubbles in the pump or unusually high water bill
Likely causes
- CommonNormal evaporation, especially in hot, dry, or windy weatherPools naturally lose up to a quarter inch or more per day from evaporation alone.
- PossibleCrack or tear in the pool liner or shellLiners can develop small tears at seams, steps, or fittings.
- PossibleLeaking underground plumbing linePressure-side or suction-side pipe leaks can lose significant water underground.
- PossibleLeak at pool equipment like the pump, filter, or heaterFittings and seals on equipment can leak, especially with age.
What to do
- Perform a bucket test: place a bucket on a pool step filled to match the pool's water level, mark both levels, and compare after 24 hours to see if the pool lost more than the bucket.
- If the pool loses more than the bucket, a real leak likely exists rather than just evaporation.
- Inspect visible pool equipment (pump, filter, heater) for wet spots or drips.
- Check the pool liner and around fittings, lights, and steps for visible tears or gaps.
- Turn the pump off overnight and see if water loss slows, which points toward a plumbing leak rather than the shell.
- For a leak that can't be found visually, a pool leak detection specialist uses dye testing and listening equipment to locate it precisely.
Tools and parts
- Bucket
- Waterproof marker or tape
Pool liner patch kitSearch: “pool liner repair patch kit”
When to call a pro
Underground plumbing leaks or shell cracks typically require a professional leak detection service to locate and repair correctly.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.