Pool Leak Detection: How to Tell If Your Pool Is Leaking

A pool that's losing water fast can cost you hundreds in water bills and thousands in structural damage if ignored. But how do you know if it's a leak or just evaporation? In Texas heat, pools can lose 1/4 inch per day to evaporation alone. More than that, and you likely have a leak. Here's how to tell, how to test, and what to do about it — from one of the few pool companies in Texas that does leak repair in-house.

Signs Your Pool Is Leaking

• Water loss over 1/4 inch per day — More than this in the absence of heavy swimmer load or extreme heat suggests a leak
• Having to add water more than once a week — If you're topping off constantly, something's wrong
• Cracks in the deck or coping — Ground shifting from water eroding the soil under your pool
• Wet spots in the yard — Soggy patches near the pool equipment or along plumbing lines
• Air in the pump — Bubbles in the pump basket or returns can indicate a suction-side leak
• Higher than normal water bills — Auto-fill devices mask the problem but your water bill tells the truth
• Algae in one spot — A leak can dilute chlorine locally, creating an algae patch near the leak
• Pool deck lifting or sinking — Undermined soil from a leak can cause deck movement

The Bucket Test: DIY Leak Check

This is the simplest way to determine if you have a leak versus normal evaporation:

1. Fill a bucket with pool water — about 2-3 inches from the top
2. Place it on the pool step — use a brick or rock to weigh it down so it doesn't float away
3. Mark the water level — draw a line on the inside of the bucket at the water level, and a line on the outside at the pool water level
4. Wait 24 hours — with the pump running normally
5. Compare the two levels — if the pool water dropped more than the bucket water, you have a leak

Important: Do the bucket test when there's no rain forecast and no one will be swimming. Turn off any auto-fill devices before testing.

Common Leak Locations

• Skimmer throat — The most common leak location. The joint between the skimmer and the pool wall separates over time from ground movement (very common in Texas clay soil).
• Return fittings — The wall fittings where water returns to the pool can leak at the seal.
• Light niche — The conduit that carries the light cord can separate from the pool wall.
• Main drain — Less common but serious. The drain at the bottom of the pool can leak at the sump.
• Plumbing lines — Underground pipes can develop leaks from tree roots, ground shifting, or age.
• Tile line — Cracked tiles and compromised grout at the waterline can allow water to escape.
• Equipment pad — Leaking valves, pump seals, filter connections — these are usually visible and easier to fix.

How We Find Leaks

Professional leak detection uses methods that go far beyond the bucket test:

• Pressure testing — We pressurize each plumbing line and monitor for pressure drops. This tells us which line is leaking, even if it's underground.
• Dye testing — We inject dye near suspected leak points (skimmers, returns, lights). The dye gets pulled toward the leak, showing us exactly where water is escaping.
• Electronic listening — We use sensitive microphones to listen for the sound of water escaping under pressure through a crack or opening.
• Underwater camera — For main drain and deep leaks, we can send a camera down to visually inspect.
• Helium or tracer gas — For difficult leaks, we inject a trace gas into the line and detect where it surfaces.

Why In-House Leak Repair Matters

Here's something most pool companies won't tell you: only about 20% of pool service companies in Texas offer in-house leak repair. The other 80% subcontract the work. That means:

• Higher cost (two companies need to make a profit)
• Longer timeline (scheduling a second company)
• Communication gaps between detector and repairer
• No single point of accountability

At Project 36, we detect and repair leaks in-house. Same team, same visit, same warranty. It's faster, cheaper, and there's no finger-pointing if something needs attention later. See our leak detection service page for details.

Leak Repair Costs in DFW

All our leak repairs come with a 1-year warranty. If the same leak comes back within the year, we fix it at no charge.

What to Do If You Think You Have a Leak

1. Do the bucket test — Confirm it's a leak, not just evaporation
2. Check the obvious — Look for wet spots around the equipment pad, dripping valves, or visible cracks
3. Turn off the auto-fill — If you have one, it's masking the problem and running up your water bill
4. Call us — The longer a leak runs, the more damage it does to your pool structure, deck, and surrounding soil. Don't wait.

Call 682-399-2593 or get a free quote online. We're one of the few companies in DFW that handles leak detection and repair in-house — no subcontractors, no runaround.