Inground pools regularly lose water each day to evaporation, but an excessive loss of water (over ½ to 1 inch per day) is indicative of a leak. Leaks must be repaired, because they not only empty a pool of its water, but also increase water bills and can weaken subsoil. Before deciding how best to repair a leak in an inground pool’s vinyl liner, however, the leak’s location must be identified and severity assessed. If you suspect that your pool has a leak, here’s how to tell whether it does and figure out where the leak is.
Identify a leak with a 5-gallon bucket
Before searching your pool for a leak, you should confirm that there is a leak. Doing so only takes one day, and all you’ll need is a 5-gallon bucket, painter’s tape and water. Simply:
- Fill a 5-gallon bucket up with water and set it next to your pool.
- Mark the water level in the bucket with painter’s tape.
- Mark the water level in the pool with painter’s tape (which won’t hurt your vinyl liner).
- After one day, measure the difference between the water level and each piece of painter’s tape.
- If the difference in the pool is greater than the difference in the bucket, then your pool has a leak; if there isn’t a significant disparity, the loss of pool water is from evaporation.
Once you determine that there is a leak, the next step is to identify where it is. (If there isn't a leak, just go for a swim.)
Check for a leak in the electrical and filtration systems
It’s easy to check the electrical and plumbing systems for leaks. Look at the electrical conduit lines that lead from the pool’s lights for moisture or leaks. There shouldn’t be any water on the wires. If there is, call a professional to determine the precise location of the leak and repair it -- you don’t want to get shocked.
To see whether your pool’s water system is leaking, turn off the filtration. Look around all pipes, fittings and the pump for moisture. If you see any, this is likely the location of your leak. Depending on the exact location of the leak, you may be able to replace a pipe yourself, or, for more complex issues like a failing pump, you might need to have a professional service your pool’s filtration system.
Look for a hole in a vinyl liner with food coloring
If your pool has a leak, but it’s not in the electrical conduits or filtration system, you’ll need to search for a leak in the vinyl liner. This is also easy to do. You will only need food coloring. Then:
- Ensure the pool is full (so the leak’s not above the water level).
- Feel the pool’s floor to see if it’s squishy, which suggests a leak in the bottom of your liner.
- Wherever you suspect a leak, place a few drops of food coloring.
- Continue placing food coloring around your pool until you find the leak.
The food coloring will let you see the flow of water. Once you place the food coloring near the leak, you’ll see it flowing out the exact spot where the leak is.
Fixing a Leak: Patches and New Liners
Once you identify where your pool’s leak is, you’ll see whether a patch will suffice. If the leak is too big for a patch, you’ll need a vinyl replacement liner. Order one as quickly as possible, so you can prevent the leak from weakening the subsoil and enjoy your pool again soon. Your vinyl liner replacement will need to be installed by a professional, so be sure to reach out to a local swimming pool builder near you.