Swimming Pool Blog

Pool Leak Detection Tools

Pool Leak Detection Tools
by Mark Garcia May 19, 2015


When it comes to locating leaks in swimming pools, technology gives the leak detection specialist or determined homeowner much needed assistance.

The basics of pool leak detection are still the primary tools of the trade however. Knowing how pool systems are plumbed, how water behaves and how to survey multiple routes for water loss, will never go out of style.

There are some fun leak detection tools on the market, mostly made by Anderson Leak Detection company, that make quick work of positively identifying pool leaks, and eliminating "guess work".

Here's some of the tools that leak detection pros use to find swimming pool leaks.

Pressure Testing

Pressure testing is the process of isolating sections of your pool plumbing, by pressurizing a pipe section and watching to see that the pressure holds, as read on a pressure gauge. Essentially, both ends of a pipe are plugged securely, with one end using a test plug, which allows for the introduction of water from a hose, or gas from a bottle, or from an air compressor.  

Air or nitrogen is used when a pipe has already been determined to leak. Adding a gas makes it easier to hear the leak when a listening device, because the gas makes a louder sound as it escapes, much louder than leaking water alone. Also, in some situations when the pool water level is too low or there is no convenient hose water source, air can substitute for water to pressurize the pipe.

  The tools used for Pressure Testing include a set of test plugs and closed plugs, and a pressure testing stick or rig, which is a short pipe of brass or plastic with a pressure gauge, and attachments for a garden hose and a regulated air source. Test plugs allow air or water to pass through, to pressurize the pipe, while closed plugs are used on the other end, to tightly seal a pipe.

Leak detection plugs are straight walled with extra large wing nuts; different from pool winterization plugs, which are tapered, and not well suited for holding much pressure. Extension plugs and plugs with inducer hoses, are further used to make the best seal, inside the pipe - not inside of a pipe fitting. Inflatable plugs are also used, which can be pumped up after inserting them into a pipe.

Dye Testing

Testing for leaks using a visible dye is a technique older than dirt ~ and you don't need specialized tools, or even specialized leak detection dye, you could use food coloring. With the pump off so the water becomes still, squirt a small amount of dye underwater, near a suspected leak. Watch the dye closely with a mask or goggles, to see if it sucks into a void, and out of the pool. Dye is commonly used around skimmers, returns and pool lights, and can be used by a diver checking a vinyl liner for small holes.

Anderson has introduced a new product, for dye testing pool lights, which are often the source of a leak (through the wire conduit), but are hard to accurately test. With the suction cup and outer gasket, the Light Tester forms a tight seal around your pool light, and allows you to administer dye through an air-tight inlet. Even without dye, you will see the water level behind the clear dome slowly fall, if the pool light niche or conduit is leaking.  

Helium Testing

Rarely needed, but in cases where the ground can't be saturated with water, or where water for pressurizing is not readily available, a small amount of helium can be pumped into an isolated section of pipe. Using a hand held helium detector, the air above the ground in a suspected area, or length of pipe is sampled for presence of helium. LED lights illuminate for the determining the area with the greatest concentration of detected helium. Draw an "X" on the ground, "dig here".

Sonic Testing

If a pipe is determined to leak using pressure testing, sonic testing is used to pinpoint the leak, to draw an "X" on the ground, so you don't have to rip up the whole pipe. With the pipe under pressure, one can use a listening device on the deck or ground above the pipes to hear the leak in action. Other listening devices allow you to hear a leak inside the pool shell, or hear it from inside the pipe, both to verify to leak and to pinpoint the location.  


A hydrophone is an underwater listening device, with a small microphone that can be snaked into pipes or moved around the pool floor or wall. Super sensitive and adjustable controls pick up the smallest underwater leak sounds, which increase in volume as you get closer to the source of the noise (leak). Also used for fountain or water feature leaks, or for leaks in natural pools.




Geophones are a mechanical device that has been used for centuries. Two circular brass sensor heads pick up vibrations underground when placed on the earth or pool deck. Connected to the sensors is a standard stethoscope listening device. They tend to pick up other environmental noise as well, but can be helpful in pinpointing the location of a pipe leak, after testing has determined which pipe is leaking.



Electronic Listening Devices

As opposed to the mechanical tools like the Geophone, or an ear on the end of broom stick, electronic listening devices amplify sounds with advanced microprocessors and filters to zero in on wavelengths from all sorts of undergound sounds. The user moves the pole mounted microphone around the deck and listens through headphones. Touch pad control panel allows independent noise suppression and optimization of target leak noises. Steel probes can also be pushed into the earth, over suspected leaking pipes.


LeakTrac 2200 is a method for locating hard-to-find leaks in the shell of the pool. When the pool leaks water with all the lines plugged and the system off, it's a safe bet it's in the shell; a crack in the plaster or a hole in a vinyl liner. A low voltage input float puts an electrical charge into the water.

Electricity will try it's best to find ground, and escape the pool, which it does quickly through small leaks in the pool shell or liner. An electric probe (on a pool pole) is moved around the pool, while listening for the 'clicks' from a small tablet worn around the neck. As the probe is brought closer to where the electricity is escaping the pool, to ground, the clicks increase in frequency. Very small, hard to find leaks in a vinyl liner or any pool shell, can be located in minutes with the LeakTrac.

Other Cool Tools

And, finally - in our list of cool tools for pool leak detection, nothing is cooler than the Nemo - a cordless and hoseless underwater drill for removing main drain covers or other wall fittings or anything else you can imagine doing underwater with a power drill. Fully waterproof, with a rechargeable 18 volt Li-ion battery. Aluminum and stainless steel construction can even be used in salt water.

Another cool pool tool used for sawing through PVC pipes in tight spaces is the wire saw. When you can't fit your reciprocating saw, or even a hacksaw into position to cut an underground pipe, a wire saw can be used. Just wrap the braided steel cable around the pipe, and pull back and forth in a sawing motion; it cuts through PVC very quickly. Tip: you can also use picture hanging wire, with the ends wrapped in duct tape.


Found all of this cool stuff at Anderson Manufacturing Company's website, leaktools.com, which also has a lot of resources on leak location and leak detection that a pool owner looking for a pool leak would find useful. Need more help? Here's some other blog posts we've done on the topic of pool leak detection:



Thanks for Reading!
Mark Garcia