Is Your Pool Losing Water? How to Tell If It's a Leak

Your pool's water level dropped again. You filled it two days ago and it's already low. Maybe it's evaporation — Texas heat does that. Or maybe your pool is leaking, and every day you wait is water wasted, chemicals diluted, and potential structural damage getting worse underground where you can't see it.

Pool leaks are one of the most expensive problems to ignore. A small leak — even a pinhole in a pipe — can waste 10,000 to 20,000 gallons of water per month. That's $100 to $200 in water bills alone, plus the constant chemical rebalancing, plus the risk of undermining your deck, foundation, or yard.

The tricky part is that not every water loss is a leak. Texas evaporation is aggressive. Splash-out from swimming adds up. Backwashing your filter uses water. Knowing the difference between normal water loss and an actual leak saves you from either ignoring a real problem or panicking over nothing.

Normal Water Loss vs. a Leak

What's Normal in North DFW

During peak summer (June through August), evaporation can account for a quarter inch to half inch of water loss per day in an uncovered pool. Over a week, that's 1.5 to 3.5 inches — which is significant and completely normal.

Factors that increase evaporation:

High temperatures (above 95°F)
Low humidity
Wind exposure
The pool is unshaded
Water features running (waterfalls, bubblers, fountains increase surface area)

If your pool has a water feature that runs continuously, it can increase evaporation by 50% or more compared to a still pool.

What's NOT Normal

Losing more than half an inch per day consistently
Water level dropping when the pool isn't being used and no backwashing was done
Wet spots in the yard that shouldn't be there
Cracks appearing in the deck or coping
Air bubbles consistently coming from return jets
The autofill system running constantly
Needing to add water more than twice a week in summer or at all in winter

If any of these describe your situation, it's time to investigate.

The Bucket Test: Confirm Whether You Have a Leak

This is the standard test every pool professional uses as a starting point. It isolates evaporation from actual water loss.

How to do it:

Fill a 5-gallon bucket with pool water and set it on the first or second step of your pool, submerged so the water inside the bucket is level with the pool water outside.
Mark the water level inside the bucket AND the pool water level outside the bucket with tape or a marker.
Wait 24 hours. Don't swim, don't run water features, don't backwash. Keep the pump running on its normal schedule.
After 24 hours, compare the two levels.

Reading the results:

If the pool level dropped MORE than the bucket level, you likely have a leak. Both should lose the same amount to evaporation — the difference is your leak.
If both dropped the same amount, you're losing water to evaporation only. No leak.
If the pool dropped more than a quarter inch beyond the bucket, the leak is significant enough to investigate.

Run the test twice for confirmation — once with the pump running and once with the pump off. If the water loss is worse with the pump on, the leak is likely in the plumbing (pressure side). If it's worse with the pump off, the leak may be in the pool shell or suction side.

Common Leak Locations in North DFW Pools

Underground Plumbing

This is the most common and most expensive leak source. PVC pipes running underground from the equipment to the pool can develop cracks from soil movement, tree root pressure, or expansion and contraction from Texas temperature swings.

North DFW has expansive clay soil that swells when wet and contracts when dry. This constant movement stresses underground pipes over time. Pools built on clay soil in Frisco, McKinney, and Allen are particularly susceptible.

Signs of a plumbing leak:

Soggy or unusually green patches of grass between the pool and equipment pad
Erosion or sinkholes near the pool
Air in the system (bubbles from return jets)
Loss of pump prime

Equipment Pad

Leaks at the equipment pad are often visible if you look carefully. Check around:

Pump housing and lid
Filter tank and multiport valve
Heater connections
Pipe unions and fittings
Chlorinator or salt cell connections

Even a slow drip from a fitting can waste hundreds of gallons per month. Tightening a union or replacing an O-ring often fixes equipment pad leaks for under $20.

Pool Shell

Cracks in plaster, pebble, or fiberglass surfaces can allow water to seep through. These are less common than plumbing leaks but do occur, especially in older pools or pools that have experienced ground movement.

Look for:

Visible cracks in the plaster (not just surface crazing, which is cosmetic)
Cracks near fittings, lights, or skimmer mouths
Tiles that have popped off the waterline
Separation between the pool shell and the coping

Light Fixtures and Fittings

The area around pool lights, return jets, skimmer mouths, and the main drain are common leak points. The sealant around these penetrations degrades over time, creating paths for water to escape.

A conduit leak behind a pool light is one of the most common leaks pool professionals find in North DFW. It's often invisible from inside the pool but shows up as water loss that stops when the pool level drops below the light niche.

Skimmer Body

The joint where the skimmer body meets the pool wall is a stress point. Ground movement, settling, or age can cause this joint to separate slightly. If you notice the water level consistently stops dropping right at the bottom of the skimmer mouth, the leak is likely at the skimmer.

What a Leak Costs If You Ignore It

Water waste: A 1-inch-per-day leak in a standard pool loses approximately 500 gallons daily. That's 15,000 gallons per month — roughly $150 to $200 in water bills depending on your municipality's rates.

Chemical waste: Every time you add water, you dilute your chemicals and need to rebalance. Over a month, this adds $50 to $100 in unnecessary chemical costs.

Structural damage: Water escaping underground can erode soil beneath your deck, causing settling, cracking, and even sinkholes. Deck repair costs $2,000 to $10,000+ depending on severity.

Equipment damage: A leak on the suction side introduces air into the system, which causes the pump to run dry periodically. Dry running destroys pump seals and motors — a $800 to $2,000 replacement.

Foundation risk: In severe cases, persistent underground water loss near a home's foundation can contribute to foundation movement. This is rare but the most expensive possible outcome.

Total cost of ignoring a moderate leak for one year: $3,000 to $15,000+

Cost of professional leak detection: $250 to $500

Cost of most leak repairs: $300 to $1,500

The math always favors finding and fixing leaks early.

When to Call a Professional

DIY leak detection has limits. The bucket test tells you IF you have a leak. Finding WHERE the leak is requires specialized equipment:

Pressure testing — pressurizes each plumbing line individually to identify which pipe is leaking
Electronic listening devices — detect the sound of water escaping underground
Dye testing — uses colored dye near suspected leak points to visualize water flow
Camera inspection — sends a camera through plumbing lines to find cracks

If your bucket test confirms a leak, call a leak detection specialist rather than starting to dig up your yard. A professional can pinpoint the exact location and often fix the issue the same day, minimizing disruption and cost.

Preventing Leaks

Not all leaks are preventable, but you can reduce your risk:

Maintain proper water chemistry. Acidic water (low pH) corrodes pipes and fittings from the inside. Keep pH between 7.2 and 7.6.
Run the pump during freezes. Frozen water expands and cracks pipes. This is the single most preventable cause of pool leaks in North DFW.
Address soil movement. If you notice your deck shifting or cracking, investigate before the movement affects underground plumbing.
Replace old O-rings and gaskets. Equipment pad fittings use rubber seals that dry out and crack over time. Replace them during annual equipment inspections.
Don't ignore small signs. A slightly soggy spot in the yard, a pump that occasionally loses prime, or a water bill that's crept up — these are early warnings. Acting on them early saves thousands.

Think your pool might be leaking? Hydra Pool Services provides leak detection and repair across Frisco, Plano, McKinney, Allen, Murphy, and The Colony. We'll find it, fix it, and save you from the damage that comes with waiting. Schedule an inspection →