How to Detect a Pool Leak: DIY Methods & When to Call the Experts

Pool leaks can occur either inside the structure or within the external plumbing. Before inspecting the pool shell itself, it's important to check the surrounding equipment - including the pump, filter, chlorinator, and heater - for visible signs of leakage.

If your pool is in-ground, leaks may stem from damaged underground pipes. In such cases, a professional pressure test may be necessary to identify the issue. But before jumping to conclusions, it’s worth determining whether you're losing water to a leak or simply to evaporation.

Method 1: The Bucket Test

This classic method can help you rule out evaporation as the cause of water loss. Here's how to do it:

1. Place a Bucket on the Pool Step
   Set a large plastic bucket on the second step of your pool. Fill it with pool water until the level matches the surrounding water. Mark the waterline inside the bucket using tape or a waterproof marker.
2. Turn Off the Pump
   Shut off the pool's circulation system and any automatic refill devices during the test.
3. Compare After 24 Hours
   Wait a full day, then check the water levels in both the pool and the bucket.
   • If both levels dropped equally, evaporation is likely the cause.
   • If the pool water dropped significantly more than the bucket, there's probably a leak.
4. Repeat With the Pump On
   Do the test again but leave the pump running this time. If the water loss increases, the issue could be in the pressurised plumbing.

Method 2: Using Dye to Pinpoint a Leak

If you've narrowed down the location of the leak, dye testing can help confirm the exact spot.

1. Get Ready
   With the pump off, move slowly in the pool to avoid disturbing the water. Bring a small bottle of pool-safe dye or food coloring.
2. Apply the Dye Near Suspected Area
   Gently release a small amount of dye near where you suspect the leak may be, such as cracks, seams, fittings, or around drains and returns.
3. Watch the Flow
   If there's a leak, the dye will flow directly toward it, helping you visually confirm the location.

Still Unsure? Call the Experts

If you're not confident in your results - or the leak seems hidden underground - it’s time to get professional help.

At Southern Leak Detection, we specialise in locating pool leaks quickly and non-invasively. Whether it’s hidden plumbing beneath concrete or subtle cracks in your structure, our trained engineers use advanced tools to identify the issue without causing unnecessary disruption. We’re here to make leak detection simple, efficient, and cost-effective for residential and commercial pools alike.