How to Tell If Your Pool Has a Leak: 7 Warning Signs

Every pool loses some water to evaporation — that’s normal, especially during San Diego’s hot, dry summer stretches. The question is how much is normal evaporation and how much might be an actual leak. Here are the signs worth paying attention to, and a simple way to check it yourself before calling in a professional.

1. Water level drops faster than evaporation explains

As a rough guide, normal evaporation is usually around a quarter-inch to half an inch per day in hot, dry, windy conditions — more with a spa spillover or water feature running. If your pool is consistently dropping noticeably more than that, or losing water even when it’s covered and not in heavy use, it’s worth investigating further.

2. The bucket test

This is the simplest way to check evaporation against your actual water loss:

1. Fill a bucket with pool water and set it on a pool step so the water levels match, or place it right next to the pool.
2. Mark the water level inside the bucket and the water level in the pool.
3. Wait 24 hours (don’t run the pool if you can avoid it during the test).
4. Compare how much each level dropped.

If the pool’s water level dropped noticeably more than the bucket’s, that’s evaporation being ruled out — and a leak becoming more likely.

3. Wet spots, soggy areas, or unexplained puddles nearby

Water tracking through soil or under decking often shows up as a consistently damp patch of lawn, a soft spot in the yard, or standing water near the equipment pad that isn’t coming from backwash or normal splash-out.

4. A rising water bill with no obvious explanation

If your water usage climbs and nothing about your household routine changed, a pool leak is a common, easy-to-overlook cause — particularly with underground plumbing leaks that aren’t visible at the pool itself.

5. Cracks in the pool shell, tile, or deck

Cracked tile, a shifting deck, or visible cracks in the pool structure can be a symptom of a leak (water undermining the surrounding soil) as much as a cause. Either way, it’s worth having someone look at it.

6. Algae or cloudiness that won’t go away despite balanced chemistry

A slow leak can pull fresh, chemically-untreated water in around the pool’s structure or plumbing in ways that make it harder to keep the water balanced, even when you’re testing and treating regularly.

7. Air bubbles or sputtering from return jets

Air in the system — bubbling from the returns, or a pump that sounds like it’s sucking air — can point to a suction-side leak in the plumbing, not just the pool shell itself.

What to do if you suspect a leak

The bucket test is a good first check, but it can’t tell you where a leak is, or whether it’s in the pool shell, the plumbing, or the equipment — and DIY dye tests around suspected cracks only work if you’re already looking in the right spot. If your results point to a leak, the next step is professional leak detection, which uses pressure testing and more targeted methods to actually locate the source instead of guessing.

We handle leak diagnosis and repair for pools across San Diego County — if any of the signs above sound familiar, get in touch and we’ll help you figure out what’s actually going on before it costs you more in water bills or damage.