DIY Pool Leak Detection: 7 Pro-Approved Tips to Find a Leak Yourself

Losing water faster than normal? Before you panic and call a pool leak detection company, try these proven DIY methods that professional technicians use every day. These tricks can save you hundreds (or thousands) of dollars by pinpointing the problem early — and if the leak turns out to be too big for a weekend fix, you’ll already have valuable info to hand the pros.

Here’s exactly how to find a pool leak at home, step-by-step.

1. Start with the Classic Bucket Test (Your Leak “Lie Detector”)

This is the #1 way to confirm you actually have a leak instead of just high evaporation.

How to do it:

1. Fill your pool to the middle of the skimmer.

2. Place a 5-gallon bucket on the top step and fill it with pool water to the same level as the pool.

3. Mark the water level inside the bucket AND on the outside of the bucket (pool side).

4. Turn off the pump and auto-fill for 24 hours.

5. Compare: If the pool drops more than the bucket (even by ⅛ inch), you have a leak.

Pro tip: Do this on a calm, wind-free day for the most accurate results.

2. The Dye Test – Pinpoint Leaks in Seconds

This is the fastest way to visually confirm a leak in the pool shell or fittings.

What you need: Pool leak dye (available online or at any pool store) OR dark food coloring in a squeeze bottle + swim goggles.

How to do it:

• Turn the pump OFF (water must be perfectly still).

• Squeeze a few drops of dye near suspected areas (skimmer throat, return jets, light niche, cracks, steps, etc.).

• Watch closely for 20–30 seconds.

• If the dye gets sucked into a crack or fitting → bingo, you found the leak.

Works like magic around lights, skimmers, and hairline cracks in gunite or plaster.

3. Inspect the Most Common Leak Hotspots

90% of pool leaks happen in these areas. Grab goggles and check each one:

• Skimmer(s): Look for cracks where the plastic meets the concrete/gunite. Press gently — does water weep out? That’s a leak.

• Return jets: Wiggle them. Any movement or gaps = potential leak.

• Pool light niche: Dye test the gasket. If water stops dropping right at the light level, this is often the culprit.

• Steps & benches: Corners crack first. Run dye along every seam.

• Main drain: Hard to see, but dye near the drain while someone watches from above can reveal suction leaks.

• Visible cracks in plaster/gunite: Even hairline cracks can leak hundreds of gallons per month.

Fiberglass pool owners: Your shell rarely cracks — focus on fittings, lights, and jets instead.

Dye pull at skimmer seam

4. Check the Equipment Pad & Visible Plumbing

Walk to your pump and filter. Look for:

• Dripping multiport valves

• Wet ground under the pump or filter

• Loose unions or cracked PVC

• Weeping backwash hose connections

A $10 O-ring or tightened union can fix many “leaks” instantly.

Leaking pipe connection at the pump found during inspection in Pompano Beach, Fl

5. The Pump On/Off Test (Tells You Pressure vs. Suction Side)

This simple trick narrows down plumbing leaks:

• Mark the water level.

• Run the pump for 24 hours → mark again.

• Turn pump OFF for 24 hours → mark again.

If the pool loses significantly MORE water with the pump OFF → the leak is in the shell or suction-side plumbing (skimmer/main drain lines). If it loses MORE with the pump ON → pressure-side leak (return lines underground).

6. Watch for “Stop-Drop” Patterns

Many leaks reveal themselves by stopping at a certain level:

• Stops right below the skimmer → skimmer throat or waterline tile leak

• Stops at the return jets → jet fitting or return line

• Stops at the light → light conduit or gasket

Keep a daily log. Patterns make diagnosis 10× faster.

7. Know When It’s Time to Call a Professional

You’ve found the leak — awesome! Now ask yourself:

• Is it a simple skimmer throat or loose fitting you can seal yourself?

• Or is it underground plumbing, a structural crack, or a main drain issue?

If it’s the second group, call a certified leak detection specialist. Modern pros use electronic listening gear, pressure testing rigs, and underwater cameras — they’ll find it without digging up your yard.

Catching leaks early saves thousands in water bills and prevents major damage (sinkholes, deck collapse, etc.).

Final Thoughts

You now have the exact same DIY pool leak detection toolkit that professional technicians use on day one of every job. Try these steps in order, document everything, and you’ll either fix the problem yourself or give the pros a huge head start.

Still losing water and can’t find it? We’re here to help. At Leak and Subsurface Locators, we specialize in non-destructive leak detection across Southeast Florida: Broward County, Palm Beach County, Martin County and St Lucie County. Contact us today and get your pool back to perfect.

Have a question or want us to check your results? Drop a comment below — happy to help!