It’s your good friend Sheleak Holmes, the world’s greatest pool leak detection specialist. In this article, I am going to discuss what are the common signs of a swimming pool leak.

So, you think your swimming pool may have a leak. That sinking feeling in your stomach as you notice the water level is lower day after day. I totally get it. As a pool owner myself, a leak is one of my biggest worries. But don’t panic just yet. There are some common signs of a pool leak you can watch out for before calling in the pros. In this article, I’ll walk you through what to look for so you can determine if your pool truly has a leak or if something else is going on.

1. Low Water Level

This is the most obvious red flag. If the water level in your pool is constantly lower than normal, that indicates water is escaping somewhere. The key word here is “constantly.” It’s normal for pool water to evaporate during hot, sunny weather. But evaporation happens slowly. If you notice the water level dropping by several inches overnight or within a day or two, that’s suspicious.

First, check your pool equipment and make sure everything is shut off. Turn off the filter pump, waterfall, slide pumps, or automatic fill valves. Check the water level the next day. If it’s still dropping rapidly, it likely means there’s a leak.

2. Pool Pump is Running Excessively

Your pool pump needs to run consistently to keep water circulating through the filter system. But if it’s running way more than normal, that could signal trouble. Pay attention to how many hours per day the pump operates. If it used to run 6 hours but now runs 12 hours or longer to maintain the water level, that points to a leak.

The pump may run nonstop because water is escaping, and the pump keeps activating to refill the pool. Or, the leak itself may be located in the plumbing system, causing the pump to work harder. Either way, an abnormally long runtime means it’s time to call in a leak detection company.

3. Higher Than Normal Water Bills

Have you noticed a spike in your water usage according to the utility bills? Does it seem like you’re refilling your pool more often than in the past? The extra water going to refill a leaky pool has to come from somewhere. If your water bills keep creeping up but your normal household usage is the same, look to the pool as the culprit.

Compare the last few months’ bills. If there’s a definite pattern of increased usage, that’s a red flag for a leak. Keep tabs on your meter readings too. Check daily to see if more water is running through the meter when the pool equipment is inactive. That’s a sure sign of a leak.

4. There Are Wet Spots Around Your Pool

Here’s a visible clue that your pool may be leaking. Walk all around the pool area and look for any wet spots or soggy soil outside the liner. Check the concrete pad around the pool edges too. Look for darker patches that indicate moisture. Grass or vegetation that’s unusually green or lush can also betray a pool leak.

Underground pool plumbing often runs beneath concrete pool decks. If there’s a leak in one of those pipes, water can escape and saturate the surrounding soil or rise to the surface. Pay special attention to areas around pool equipment like pumps, filters, and heaters. A leak near connections in that plumbing could create visible water spots.

5. Pool Surface Cracks or Discoloration

Carefully scan the liner or concrete/plaster interior of your pool. Look for any cracks, splits, or blisters in the surface. Also, watch for any lighter or darker-colored patches. A stain indicates water is seeping out and depositing dissolved metals and minerals that alter the surface.

Cracks typically appear near steps, edges, drains, or skimmer inlets first, as those areas endure the most wear and tear. Even barely visible surface cracks can still leak a lot of water. You may see water bubbling up from cracks when the pool is in use. Even without obvious moisture though, cracks signal the pool surface is degrading and likely leaking.

6. Lower Pressure on The Pool Filter

The filter system on your pool works by continually circulating water and maintaining consistent pressure. If there’s a leak somewhere downstream of the filter, pressure drops. Check the filter pressure gauge regularly. If you notice it’s lower by 5-10 PSI or more from the normal level, follow the steps above to confirm if there’s a corresponding leak.

Here’s a simple test after checking the pressure: Turn off all pool equipment and do not add water for 24 hours. The next day, turn the pump back on briefly and recheck the filter pressure gauge reading. If it’s still low, that points to a leak rather than normal pressure fluctuation.

7. Mold, Loose Tiles, or Hollow Sounds

Here are a few other structural anomalies that can indicate an underwater leak. Inspect the pool walls and floor for any missing or hollow-sounding tiles, cracks, or loose grout. Leaking water can erode the mortar behind surface materials over time. Any mold, mildew, or dampness inside corners or the skimmer also warrant a closer look.

For concrete pools, scan for cracks, chips, or stains on the interior surface. Knock on the walls and listen for any obviously different sounds that signal delamination underneath. Pay special attention to the floor around the main drains as a leak here is common. Any deterioration or soft spongy areas mean water is escaping under the pool shell.

Don't Waste Time - Call in the Experts

If you suspect your pool has a leak based on one or more of these signs, don’t drag your feet. Call a professional leak detection services company like USA Leaks to inspect, identify the source, and make repairs. The sooner you get an expert opinion, the less water you’ll waste and money you’ll drain from your wallet.

Most leak detection firms offer free consultations and estimates and can determine if your leak falls under warranty coverage. Catching and repairing a leak quickly saves thousands of gallons of water and prevents costly structural damage long-term. And you’ll have peace of mind knowing your pool isn’t losing water every time you take a dip!