swimming pool leaking with the filter on

[vancouverlangley123]

My swimming pool has been losing water these days.
The problem is that once the water level droped below the skimmer, it stoped droping. And If I turned off the filter, it would also stop losing water.
I am really confused right now since I am not very famaliar with swimming pool because I have just purchased the house.

Could someone help please..

[Larry]

If the water level stops dropping once it gets below the skimmer, then the leak is most likely somewhere in or around the skimmer box or suction line.

If I turned off the filter, it would also stop losing water

Do you mean turn off the pump or close the valves?

Larry

[vancouverlangley123]

If the water level stops dropping once it gets below the skimmer, then the leak is most likely somewhere in or around the skimmer box or suction line.

If I turned off the filter, it would also stop losing water

Do you mean turn off the pump or close the valves?

Larry

thank you for your reply.
if I turned off the pump, the water remains at the same level.

[Guest]

Hey there

Sounds like a leak on the return line. If the pump is not drawing air, then you can bet it is pushing water out a crack or hole on the pipe that goes back to the pool.

[vancouverlangley123]

Hey there

Sounds like a leak on the return line. If the pump is not drawing air, then you can bet it is pushing water out a crack or hole on the pipe that goes back to the pool.

Hi
thank you for your reply

I know very littlbe bout swimming pool, so is the return line underneath the ground or it's visible in the pump room. By the way, I assume that the pipes in the pump room are not leaking cuz it's pretty dry in that room...

cheers

[Larry]

If the pump room is dry then the problem is on the waste line or it is underground. Is there a valve on the waste line? Can you monitor the end of the pipe while the pump is running to check if water is being discharged?

Sometimes a subsurface leak can be detected by a damp patch of dirt or abnormal vegetation growth near the pool. If not, you really need to determine exactly which pipe is leaking before attempting a "dig and repair".

Larry

[ChuckGeo]

I agree that the problem may be the return line, but further tests are necessary. I'd recommend filling the pool to it's normal level, mark the water level and leave the pump off for 24 hours (during non freezing weather). Measure the loss after 24 hours. Refill the pool, if necessary, mark the level and run the pump for 24 hours then measure the loss. Compare the water loss measurements - if they are the same, suspect a structural leak. If the water loss stops at the bottom of the tile I'd suspect the skimmer throat where the plastic skimmer butts up to the concrete or tile in the throat.
If the water loss is greater with the pump on, suspect the return line. To confirm this the line will have to be pressure tested.
If the loss is less with the pump on, suspect a suction line - skimmer or main drain. Pressure testing is necessary to confirm the leak.

Good luck.