Swimming pools are a great form of recreation, and many pool owners pride themselves in keeping their pools in good working order. If a leak develops in your pool, however, you may find yourself unsure of how to find it or repair it. Repairing a leaking pool isn't necessarily difficult, though finding the exact location of the leak isn't always easy. You first must confirm that there is an actual leak and that the loss of water isn't due to evaporation, then you can begin locating and repairing the leak.
Discovering If There Is a Leak
Shut down the pool's pump.
Fill a large jar or other open-topped container with water and place it on the top step of your pool ladder. Pick the jar or container up and pour out water as needed until the water in the jar is level with the water in the pool when the jar is placed back on the ladder.
Wait one or two days, not allowing anyone into the pool during this time. Check the water level in the jar; if it is approximately the same height as the pool water then there isn't a leak inside the pool itself. If the pool water is lower than that of the jar, then there is a leak inside the pool.
Turn the pump back on if the water level remained the same inside and outside of the jar. Allow the pump to run as normal for one to two days.
Check the water level again. If the pool's water level has dropped below that of the jar, there is a leak in the pumping and filtration system.
Leaks in the Pool
Shut down the pump, allowing enough time for the water to become still.
Examine the pool liner for signs of tears or other damage that could be the cause of your leak. Check the ground around the pool for puddles or other signs of water to help you narrow down the area where you should search. Check seams, underwater light fixtures, and filter or pump connections as well. If you suspect an area of being the leak but aren't sure, place a few drops of food coloring near the suspected leak and see if it flows toward the area.
Use a grease pencil or other waterproof marking tool to mark the spot where the pool is leaking. Drain the pool to the point where the leak is exposed to air. Wait several hours to a day so that the area has time to dry.
Apply silicone or other waterproof sealant to the leak, working it into the crack or hole if it is a larger leak. Smooth the sealant so that it completely covers the leak, then allow it time to dry.
Refill the pool and turn the pump and filtration system back on. Monitor the area for signs of additional leakage, repeating the repair process if needed.
Leaks in the Pump System
Shut down and unplug the pump.
Examine the water lines that connect the pool to the pump and filter. Look for puddles or wet areas on the ground beneath them and feel the pipes to see if they are wet.
Plug the pump back in and turn it on if you aren't able to find signs of leakage. Examine the water lines again while the pump is working, paying special attention to seams and joints in the line. Unplug the pump again once you have located the leak.
Apply silicone or another waterproof sealant to the leaking area if it is a small leak in the water lines. If it is a larger leak or the leak is coming from the pump or filter itself, replace the section of pipe or the pump system component that is leaking.
Allow any sealant that you applied time to dry, then wrap it in waterproof tape to provide additional support against leaks. Restart the pump and check the repaired section for signs of additional leakage, performing additional repairs if necessary.