Suction Side Leak - Water Loss - Can't find anything??

JD880

Active member
Jun 20, 2014
30
Wayne, NJ
Hi I have a large vinyl liner inground pool - no main drain or pool lights, just 2 skimmers and 3 return jets. Losing about 1-1.5 inches of water for every 12 hours when the pump is off overnight.

No water loss when the pump is running, have tested this a few times already.

Figured it must be a skimmer or suction side pipe leak but I've dye tested every crevice and face of both skimmers and nothing. Shut down both skimmer lines to see if it is the underground lines, tested with dye but nothing was sucked down.

I'm at a loss here I'm filling the pool daily. I've also shot dye around all the return jets, pool steps and nothing. It can't be the liner if it only loses water when the pump is off right? Looking for any advice here. Thank you!
 
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do you have air in your pump basket? it is not usual for no water loss when the pump is running and all water loss with pump off...
 
do you have air in your pump basket? it is not usual for no water loss when the pump is running and all water loss with pump off...
Hi, no not really any air bubbles, just a couple at the top of the pump, but it's always been like that before the water loss started. No water coming out anywhere in the pump/filter area, on or off, I've checked all the plumbing, unions, etc.
 
If there are no bubbles in the pump basket you do not have a suction side leak and if the water is going down with the pump OFF then the leak is not in the pressure side of the pipe...

I really want to say it has to be in the pool.. The water will always stop going down at the leak... have you let is go down until it stops? the problem with this is it may not be at the top of the pool.... 3 inches in 24 hours is a big hole...

Have you done a bucket test to see how much water loss your getting from evaporation?
 
If there are no bubbles in the pump basket you do not have a suction side leak and if the water is going down with the pump OFF then the leak is not in the pressure side of the pipe...

I really want to say it has to be in the pool.. The water will always stop going down at the leak... have you let is go down until it stops? the problem with this is it may not be at the top of the pool.... 3 inches in 24 hours is a big hole...

Have you done a bucket test to see how much water loss your getting from evaporation?
The return jets do shoot out a lot more bubbles for about the first 30 seconds when turning on pump, but then go fully away and appears to operate normally.

Ive done the bucket test overnight to verify, no loss in bucket but just over an inch lost in same period from pool (measured with markings at both skimmers).

I have only let the water get down just enough where the skimmer starts sucking air, then refill. I was hoping its not the liner as it only happens when the pool pump is off, but is this possible somehow? I have an old liner (est. 20+ years) and already have put down a deposit for a new one before this bad leak started occuring but it's backordered until fall.
 
it really is crazzy it is only happening while the pump is off... Well the easy way to fix this until the fall is to run your pump till the fall.. not sure if you have a 1 speed and what it will cost you.. does water or electricity cost more?

I wonder if it could be at the return and when the pump is running it is pushing water away fast enough to where it will not leak... You said you checked them.. 1.5 inches in 12 hours is a big leak...
 
it really is crazzy it is only happening while the pump is off... Well the easy way to fix this until the fall is to run your pump till the fall.. not sure if you have a 1 speed and what it will cost you.. does water or electricity cost more?

I wonder if it could be at the return and when the pump is running it is pushing water away fast enough to where it will not leak... You said you checked them.. 1.5 inches in 12 hours is a big leak...
Ha I think the electricity is more expensive then filling water. Another note, since I posted this morning, the weird thing is only 1 of the 3 return jets in the pool are still shooting bubbles even though the system has been on all day. This makes me more confused since from the pump/filter there is only 1 return line that goes out into the yard then it splits off into 3 return jet lines where I can control each of them with a ball valve. Just noticed this as I've been watching the pool all morning.
 
if there is not air in your pump and filter but there is air coming from your return then that is where the hole is.. somehow it is not shooting water out when it is running it is sucking in air.. when the pump turns off it leaks out the hole in the pipes... it could also be the ball valves as they are really bad and go bad very fast.. A neverlube Jandy valve is much better and last years with no issues. mine are 9 years old now and are still perfect...
 

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Plug your skimmers. Remove the basket cover at the pump and fill with water. Leave cover off and pump off and see if the water in the basket drops.
When I turn off/plug the skimmers, even if I remove the pump cover, water gushes out. Should I turn the multiport to off? Otherwise I'm guessing the filter is draining itself.
 
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