10 Warning Signs Your Pool Might Have a Hidden Leak

Not all pool leaks are dramatic, obvious gushes of water. Many start small, so small you might not even realize something’s wrong. That’s the danger. These hidden leaks quietly chip away at your pool’s structure, water balance, and equipment, leading to big bills later.

If you own a pool in New Jersey, especially during high-use months, you need to know the early indicators. Here are the 10 most common signs your pool might have a hidden leak, and what you should do about it.

1. Unexplained Water Loss

Losing water is normal, up to ¼ inch per day from evaporation in summer, but if your pool is dropping more than that consistently, especially overnight or in cooler months, a leak could be the culprit.

What to check: Use the bucket test to measure loss. If the pool water drops more than the water in the bucket, you likely have a leak.

2. Difficulty Maintaining Water Chemistry

Are you constantly adjusting pH, chlorine, or alkalinity? When water leaks, chemicals leak too, making it nearly impossible to keep balance.

Why it matters: Unbalanced water causes swimmer irritation, algae blooms, and damages surfaces and equipment.

3. Sudden Increase in Water Bills

If your auto-fill line is constantly running to make up for lost water (and you don’t realize it), you may not notice the leak until your water bill arrives and it is 3-5x more than normal.

Pro tip: Compare your current water bill with the same month last year. A sharp increase could point to a hidden leak.

4. Algae Growth Despite Chlorination

If your pool is well-maintained but algae keeps returning, it could be due to diluted chlorine from a leak. Algae thrives in low-sanitizer environments.

Warning sign: Green or yellow tints in corners or near steps, especially if recurring.

5. Air in the System

Notice bubbles blowing from return jets or a gurgling inside the pump? Leaks in the suction line can draw in air.

Common signs: Bubbling, loss of prime, pump running loud or inconsistent.

6. Cracks in the Pool Shell or Deck

Hairline cracks may seem harmless, but they can let water escape, or indicate shifting due to soil erosion beneath your pool.

Red flag: Cracks around the skimmer, lights, return fittings, or tile lines.

7. Wet Spots Around the Pool Area

Muddy patches, spongy grass, or shifting pavers can indicate underground plumbing leaks.

Watch for: Persistent wetness even during dry weather.

8. Low Water Under the Skimmer

If your water level keeps falling below the skimmer despite refilling, you may have a leak.

Solution: This needs urgent attention, because the pool pump can be damaged if the water goes below the skimmer while the pump is running.

9. Pool Losing Prime Overnight

If your pool pump loses its prime after being off overnight, it may be sucking in air due to a leak in the suction line or pump components.

What to look for: Difficulty restarting the pump each morning or drop in pressure on the gauge.

10. Increased Use of Auto-Fill System

Auto-fills are convenient, but they can also hide leaks. If yours runs constantly or you notice higher water bills, it could be compensating for a leak you can’t see.

Tip: Monitor your auto-fill usage for a few days to see if it’s working overtime.

What Should You Do If You Suspect a Leak?

Don’t wait until your pool is green, cracked, or costing you hundreds (if not thousands) more per month. If you notice even one or two of the signs above, call a professional pool leak detection service in New Jersey. They’ll diagnose the issue quickly, often using pressure tests, dye tests, or sonar equipment, without damaging your pool.

When Small Signs Lead to Big Repairs

What might start as a $200 fix can become a multi-thousand-dollar problem if you let it linger. Ignoring signs of a leak can lead to:

• Soil erosion under your pool
• Structural damage and resurfacing
• Burned-out equipment
• Complete plumbing replacements

Early Detection = Long Term Savings

Your pool is meant to be a source of relaxation, not stress. By staying alert to early warning signs and scheduling regular inspections, you’ll protect your investment and enjoy a clean, safe pool all season long.

If your pool in New Jersey is showing any of these signs, don’t wait. Reach out to Atlantic Pool Leak Detection to schedule a professional inspection today. Fix it now, and save later.

Categorised in: Pool Leak Inspection