Swimming Pool Blog

How's the pool water level - is your pool leaking?

How's the pool water level - is your pool leaking?
by Rob Cox, January 27, 2011


How's the pool water level - is the pool leaking?



Pools can lose water during the winter. Underneath a snowy pool cover, it's sometimes hard to spot, but a winterized pool leaking water is never a good thing.

Vinyl liner pools can leak from almost anywhere, and most suspect is any area that was purposely cut - for wall returns, lights, skimmers and step sections. Concrete pools commonly leak around the skimmer and the underwater lights.


Winterized pools, or those that had the lines blown out and plugged at the pool, should not be leaking if properly sealed, so any leaks on a winterized pool should be coming from the pool shell.

Do you have a solid winter pool cover? Small holes in a solid cover can allow you to pump out pool water - trough the holes and out via your pool cover pump. Using an air blower under one end of the pool cover can help inflate a solid pool cover, pushing all water to one side, where it can be more easily pumped off. This also makes it easy to spot new water "bleeding" onto the pool cover as it settles back into place.

Any pool type leaking during winter should not be allowed to drain completely. This can cause havoc on vinyl or concrete pools. Add water to your pool if a leaking pool drops within 1 foot from the shallow end floor. Vinyl liners will relax and wrinkle, possibly cracking or "snapping", and concrete pools risk cracking, drying of plaster finish and popping out of the ground due to hydrostatic pressure.

It is good practice however, to allow a pool to leak down to the light, and/or below all wall returns or fittings. If the leak will "stabilize" at the middle of the light, for instance, we may want to remove the lamp and inspect the light niche and where the conduit connects in the rear of the light "bucket". This can be sealed with swimming pool leak repair products like pool putty, silicone or a cord seal plug.

Likewise, if the water level has stabilized at a wall fitting, dye testing around this area can determine an area in need of patching using pool putty or a vinyl liner pool patch kit. If the pool continues to lose water level, dropping below lights and returns, watch it carefully and inspect the water level areas closely, using a dye test syringe and a close eye to look for small cracks or tears in vinyl liners.

For more information on locating pool leaks, see an earlier blog post on locating pool leaks.