The Aquafone LD underwater microphone is designed to find leaks and hear those whooshing sounds from inside the water. When you put the microphone into the pool, you’re going to move around the edges of the pool, listening for that whoosh at the places where cracks and separations are known to form. Because a pool is made of solid concrete, the areas where separations typically happen are where plastic pipes and fittings come through the concrete. This means drains, return fittings, lights and places where you attach your floor cleaner. All of these protrusions are up against concrete, and sometimes they stop adhering to the concrete because of regular use, chemicals in the pool and ground movement.
Some of these areas, including where the coping and bond beam in the pool are, can be above the water line. The water has leaked out and is now down to the level where the crack or separation occurred. There’s no water going out of it because it drained down to the bottom of the crack. To hear the water whooshing out of that crack, we need to fill the pool back up to its proper level. When the water is back up to the top, its weight will start to push out of the crack again and we can listen for it escaping with the Aquafone LD underwater microphone.
Know that when a pool sits, without water up against its shell, it can dry out. The plaster on the pool surface becomes dry, especially in the sun. When you toss a hose into the pool and bring the water level back up, the plaster is going to absorb that water and re-hydrate. During this process, the plaster is going to make a crackling or bubbling sound. If you put the Aquafone LD underwater microphone in the pool right away, you’re going to hear that sound. It’s like a bowl of crispy rice cereal, and sometimes it even makes bubbles.
To get the best results when listening to find leaks, make sure the pool is filled, but wait a couple of hours after filling to be sure that the plaster is fully hydrated. At that point, listening inside the pool, with the equipment all turned off and the water still, you’ll be able to hone in on the area where the whoosh is taking place and you’ll find right where the leak is. Check for certain with a quick dye test and apply the method of repair you need to make the water loss stop and then get ready for a swim.