Why Is My Pool Losing Water So Fast in the Summer?

As the June heat settles over North Texas, homeowners from Plano to Fort Worth are finally peeling back the covers and diving into the swim season. But after a few weeks of triple-digit heat and that relentless DFW wind, you might notice something unsettling: the water line is dropping. Fast.
It starts with a suspicion. You look at the tile line on Monday, and by Thursday, the water is clearly an inch or two lower. Your first instinct might be panic. Is there a crack in the foundation? Did the winter freeze finally claim a pipe? Or is this just the legendary Texas sun doing its thing?
Understanding the difference between pool water evaporation and a legitimate pool leak is the most important part of summer pool maintenance.[1] In this guide, we’re going to break down why your pool is losing water, how to test it yourself, and when it’s time to call in the pros before you burn out an expensive pump.

How Much Water Loss Is Normal?

In North Texas, “normal” water loss can feel like a lot. We aren’t exactly known for our humid, stagnant air in the summer. Instead, we get a combination of high heat, low humidity, and constant wind—the “triple threat” of evaporation.

Typical Summer Evaporation Rates

Under standard conditions, a swimming pool typically loses about 1/4 to 1/2 inch of water per day. Over a week, that translates to roughly 2 to 4 inches. If you have a large pool (say, 15,000 to 20,000 gallons), that is hundreds of gallons of water literally vanishing into thin air every single week.

The Science Behind the “Thirsty” Pool

Several factors in North Texas accelerate this process:

• The Heat/Cold Cycle: In June, we often see 95-degree days followed by slightly cooler nights. When the air temperature drops but the pool water remains warm, evaporation accelerates. If you’ve ever seen “steam” rising off your pool in the early morning, you’re watching your water level drop in real-time.
• The Wind Factor: Wind is the enemy of a full pool. As wind blows across the surface, it carries away the humid air directly above the water, allowing more water to evaporate. In open areas like Frisco or Prosper, where there are fewer trees to break the wind, pools often lose water faster than those in heavily wooded neighborhoods.
• Water Features: If you have a rock waterfall, deck jets, or a tanning ledge with bubblers, your evaporation rate will be higher. These features increase the surface area of the water and expose it to more air, turning your pool into a giant humidifier.

Signs You May Have a Leak

While evaporation is a fact of life for a swimming pool losing water, it isn’t always the culprit. Because our North Texas soil is primarily heavy clay, it expands and contracts violently with the seasons. This shifting can put immense pressure on underground PVC pipes or even the pool shell itself.

Identifying Potential Leak Sources

If you suspect a leak, look for these “red flags”:

• The “Losing Ground” Test: If you are losing more than half an inch a day (or more than 3 inches a week) and you don’t have a massive waterfall running 24/7, you likely have a leak.
• Wet Spots Around the Equipment: Take a walk around your pump and filter. Is the ground soggy? Are there puddles forming near the heater? Even a small drip from a “skimmer o-ring” or a “union” can waste gallons over time.
• Air in the Circulation System: If you see bubbles coming out of your return jets (the holes in the wall that push water back into the pool) or if the water in your pump basket looks like a washing machine full of bubbles, you have a “suction side” leak. This means air is being pulled into the pipes, usually through a crack or a loose fitting.
• Structural Cracks: Keep an eye on your tile line and the “coping” (the stone border around the top). If the pool is settling due to shifting clay soil, you might see cracks in the grout or tiles popping off. These are often signs of a structural leak.

The DIY “Bucket Test”

Before you spend hundreds on a leak detection specialist, do this simple, 24-hour test:

1. Fill a 5-gallon bucket with pool water.
2. Set it on the first or second step of the pool (it should be submerged a few inches so the water temperature stays the same).
3. Mark the water level inside the bucket and the water level outside the bucket with a piece of tape.
4. Wait 24 hours. If the pool level (outside mark) dropped significantly more than the bucket level (inside mark), you have a leak. If they dropped the same amount, it’s just evaporation.

Why Low Water Levels Matter

It might seem like a minor annoyance—just “put the hose in for an hour”—but ignoring a dropping water level can lead to a multi-thousand-dollar repair bill.

Pump Damage and Cavitation

Your pool pump is designed to move water, not air. If the water level drops below the mouth of the skimmer (the square opening in the side of the pool), the pump will start “sucking air.”
This causes cavitation, where the pump loses its “prime” and begins to run dry. A dry-running pump generates massive amounts of heat, which can melt the internal seals, warp the plastic housing, and ultimately burn out the motor. Replacing a high-end variable speed pump can easily cost $1,500 to $2,500.

Circulation and Algae Issues

When the water is low, your skimmer can’t do its job. It won’t pull leaves or debris off the surface, meaning all that organic matter sinks to the bottom. Furthermore, if the pump is struggling to pull water, your filtration slows down. Stagnant, warm water in the North Texas sun is a recipe for a “green” pool. You’ll find yourself spending more on chlorine and phosphate removers just to keep the water clear.

When to Call a Professional

If your bucket test confirmed a leak, or if you can see water pooling where it shouldn’t be, it’s time to call in a professional. DIY leak detection is notoriously difficult because most leaks happen underground or in the “light niches.”

What to Expect During a Professional Inspection

A pool professional will use several specialized tools to find the source:

1. Pressure Testing: They will plug the lines and use a pressure gauge to see if the underground pipes are holding water.
2. Dye Testing: If they suspect a crack in the shell or around the skimmer, they’ll use a special syringe filled with colored dye to see where the water is being sucked out.
3. Electronic Listening Devices: For deep underground leaks, pros use sensitive microphones to “hear” the sound of water escaping into the soil.

Don’t Let the Soil Win

In DFW, we always recommend keeping a “moisture perimeter” around your pool. During the height of summer, the clay soil can pull away from the pool deck, causing it to crack or “drop.” Using a soaker hose around the pool area can help stabilize the ground and prevent the structural leaks that are so common in our region.

Stay Ahead of the Heat

A pool losing water is one of the most frustrating parts of being a homeowner, but it doesn’t have to ruin your summer. By monitoring your levels weekly, performing the bucket test at the first sign of trouble, and understanding the unique challenges of the North Texas climate, you can keep your equipment safe and your water crystal clear.

Don’t ignore dropping water levels during summer. A little vigilance today can save your pump—and your wallet—tomorrow. If you’ve ruled out evaporation and the bucket test shows a leak, reach out to a local specialist immediately to get your backyard oasis back in top shape.