Rapid leak slowing down

[michael734]

Hi

Our pool had been suffering a rapid leak and we had lost about 2cm a day (around 1kL). Today it suddenly stopped/slowed significantly. The water level now is about 20cm off the top of the pool. We've checked the waste line and it's fine. Does anyone know why the leak might stop at a lower water level? I can't see any obvious crack in the tiles around the current water level though. At around 0.7L/min, I'd expect a rather large crack.

Any tip would be much appreciated.

[Denniswiseman]

Hi

Our pool had been suffering a rapid leak and we had lost about 2cm a day (around 1kL). Today it suddenly stopped/slowed significantly. The water level now is about 20cm off the top of the pool. We've checked the waste line and it's fine. Does anyone know why the leak might stop at a lower water level? I can't see any obvious crack in the tiles around the current water level though. At around 0.7L/min, I'd expect a rather large crack.

Any tip would be much appreciated.

If the water stopped leaking at the level it's at, that is where your leak is.
Are there any pipe connections to the pool at that level as the leak may be in pipework and not the pool
20cm from the top of the pool isn't to low, does your skimmer still work

[michael734]

If the water stopped leaking at the level it's at, that is where your leak is.

That's my thinking too. However, I can't see any crack in the tiles or grout. I've tried dye testing areas inside the pool that look suspicious, but there's no suction.

Are there any pipe connections to the pool at that level as the leak may be in pipework and not the pool
20cm from the top of the pool isn't to low, does your skimmer still work

Yes, the skimmer still works - but barely. I can't quite tell the height of the pipes, because all of the underground plumbing is under a concrete slab. Is there any way to find out the height without digging up the concrete?

[Denniswiseman]

I would suggest getting some expandable pipe plugs, block off the returns and skimmer and refill
If it holds then the poolis intact and the leak is in your pipes
Unblock the skimmer first and see if the level drops if it doesn't then the leak is in your returns

[michael734]

I would suggest getting some expandable pipe plugs, block off the returns and skimmer and refill
If it holds then the poolis intact and the leak is in your pipes
Unblock the skimmer first and see if the level drops if it doesn't then the leak is in your returns

How about the main drain? At the bottom, we have one suction main drain. If we leave that one unplugged, could water leak out from that?

[Denniswiseman]

I would suggest getting some expandable pipe plugs, block off the returns and skimmer and refill
If it holds then the poolis intact and the leak is in your pipes
Unblock the skimmer first and see if the level drops if it doesn't then the leak is in your returns

How about the main drain? At the bottom, we have one suction main drain. If we leave that one unplugged, could water leak out from that?

Water seeks it's own level so if the leak is in the main drain it would be at the height of the water in the pool
Where is your pump in relation to the pool. Higher or lower
The fact that it is only 20cm down is a bonus as excavation wouldn't be horrendous
You could also try plugging the main drain if that is possible

[michael734]

Water seeks it's own level so if the leak is in the main drain it would be at the height of the water in the pool
Where is your pump in relation to the pool. Higher or lower
The fact that it is only 20cm down is a bonus as excavation wouldn't be horrendous
You could also try plugging the main drain if that is possible

Our pump is higher than the pool (pool is inground and pump is at ground level).

So if I leave just the main drain unplugged, is it right that leakage could still stop at 20cm after refill since the main drain is connected to the rest of the plumbing? But perhaps if I leave just the main drain unplugged, dye testing a return should be more obvious.

The biggest problem is that all the pipework is under concrete...

[Denniswiseman]

Normally the main drain and skimmer go right back to the pump and have valves or 3 way valve to regulate the flow between them
I would go for blocking up what you can and testing with a full pool
I'm afraid that the concrete will have to be broken if pipes are leaking but it's only 20cm down and would be the lesser of two evils

[michael734]

Normally the main drain and skimmer go right back to the pump and have valves or 3 way valve to regulate the flow between them
I would go for blocking up what you can and testing with a full pool
I'm afraid that the concrete will have to be broken if pipes are leaking but it's only 20cm down and would be the lesser of two evils

My setup is quite simple and unfortunately I don't have any valve at all above ground. I'll try to close off as much as I can and see! Hopefully we won't have to smash up the concrete.

Thanks for the advices.

[Denniswiseman]

Come back Michael and let us know how you got on
Good luck