What Are the Signs of a Pool Leak?

Pools lose water naturally through evaporation, splashing, and backwashing—but if your water level is dropping faster than normal, you could be dealing with a leak. And while a little water loss may not seem like a big deal at first, an undetected pool leak can lead to expensive repairs, wasted water, and even structural damage over time.

So how do you know if it’s a leak or just summer heat at work? Let’s break down the most common signs of a pool leak and how to confirm it before it becomes a major problem.

Not all leaks are dramatic. Some are slow, subtle, and easy to overlook—until the damage starts adding up. Here are the red flags to watch for:

1. Unexplained Water Loss

If your pool is losing more than ¼ to ½ inch of water per day, that’s more than evaporation. A consistent drop in water level is one of the most common—and clearest—signs of a leak.

2. Soggy or Eroding Spots Around the Pool

Are there constantly wet patches near your pool deck or landscaping? Soft spots, sinking areas, or eroding soil can indicate water is escaping underground.

3. Increased Water Bills

If your pool is on an auto-fill system, a hidden leak might go unnoticed—until you get hit with a higher-than-usual water bill. Always compare your current usage with previous months if you suspect something’s off.

4. Cracks in the Pool Structure

Hairline cracks in your pool’s surface, tile, or decking may seem small, but they can be entry points for leaking water—especially if they grow over time or feel damp.

5. Algae or Chemical Imbalance Issues

Leaking water throws off your pool chemistry. If you’re constantly adjusting chlorine or pH levels or seeing frequent algae growth, the cause could be dilution from a leak.

6. Air Bubbles in the Pump System

Air entering your plumbing system is another potential sign. If your pool pump is spurting air bubbles or losing prime, it might be sucking in air from a leak in the suction side of the plumbing.

Think you might have a leak? Here are a few simple methods to help you investigate further before calling in the pros.

Step 1: Do the Bucket Test

This classic test can help you tell the difference between evaporation and a true leak.

Here’s how:

1. Fill a bucket with pool water and place it on the pool step (partially submerged).
   
   
2. Mark the water level on both the inside and outside of the bucket.
   
   
3. Wait 24 hours and compare.
   
   

If the pool water level drops more than the water inside the bucket, you likely have a leak.

Step 2: Turn Off the Pump and Observe

Leaks in the plumbing system will often slow or stop when the pump is off. Monitor your water level with the system running and again after turning it off overnight. If you see a difference, the leak may be in the pipes.

Step 3: Inspect Equipment and Plumbing

Check the pump, filter, heater, valves, and connections for any visible drips, puddles, or signs of water loss. Leaks in the equipment pad area are relatively common—and usually easier to repair.

Step 4: Look for Dye Movement

For suspected structural leaks (around cracks, fittings, skimmers, etc.), use food coloring or pool leak dye:

• Shut off the pump and allow the water to become still.
  
  
• Squeeze a small amount of dye near the suspected area.
  
  
• If the dye pulls toward a crack or seam, you’ve found a leak.
  

Some leaks are easy to detect and fix—but others require professional tools and expertise. If you’re still not sure what’s causing your water loss or you’ve found signs of damage to your pool’s structure or plumbing, it’s best to bring in the pros before the problem gets worse.

At Blue Oasis Pools, we offer expert leak detection services using advanced tools like pressure testing and electronic listening devices. We’ll find the leak, diagnose the cause, and recommend a fix that fits your timeline and budget.

A little water loss might not seem like a big deal—until it starts damaging your pool, yard, or wallet. Staying alert to the signs of a pool leak and knowing how to detect it early can save you time, money, and stress in the long run.

Think you might have a leak? Let Blue Oasis Pools help you find and fix it fast. Contact us today for professional pool leak detection and repair.

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