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How To Find A Leak In A Pool Liner

There are fewer thoughts scarier to swimming pool owners than that of water leaking from somewhere on the vinyl pool liner of their in-ground pool. And that’s why it's important to find a leak in the pool liner.

Yes, a leak might be able to be repaired with a relatively simple patch. But, at the other end of the spectrum, the pool might need to be drained, the ground supporting the pool re-levelled and a new vinyl liner installed.


Finding a Leak in a Pool Liner

Locating a leak in your swimming pool starts with confirming that there is a leak.

  1. Confirm that the Pool is Leaking - Get fill a 5-Gallon bucket with water and place it beside the pool. Use a grease pencil or piece of tape to mark the water level at a point about one inch above the waterline in the bucket and in the pool.

    After 24 hours compare the difference in the water levels in the bucket and in the pool. If the pool’s water level has dropped noticeably more than the bucket’s water level, you have a leak. If the levels are about the same as each other, then the loss of pool water is due to evaporation, not a leak.
  2. Check the Pool’s Equipment - Leaks can happen at any point where water is present or travels. That means you must check the plumbing systems, filtration systems, around light housings and the pool pump for signs of leaks.

  3. Use Red Food Coloring to Find a Leak in the Liner - If the leak isn’t in the equipment, then it's in the liner. When water leaks from a liner it can leave a few tell-tale signs. As the water gets out from the pool it will weaken and wash away dirt from outside the pool. That will leave a depression in the liner around the leak. You can use your hands, feet and eyes to inspect as much of the pool as possible.

    If you find one or more unusual or new depressions that you suspect may indicate leak points, release a few drops of red food colouring near the depression. Watch the food colouring which, if it is near the leak, it will flow towards the leak. Then you need to call your inground pool installer for help.

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