My pool leaks. How do I find the leak?

[iNow]

4 hours ago, Genady said:

I'd like to narrow it down as much as possible.

Grab a soil moisture probe and start poking around in a grid pattern. Record measurements taken within each cell of your grid and see where it’s wettest

https://www.bestbuypick.com/elite/best-5-soil-moisture-meters-of-2024-2/

Do it every foot or 2 for more granular precise measures

https://www.bobvila.com/articles/best-soil-moisture-meter/

[Genady]

1 hour ago, iNow said:

Grab a soil moisture probe and start poking around in a grid pattern. Record measurements taken within each cell of your grid and see where it’s wettest

https://www.bestbuypick.com/elite/best-5-soil-moisture-meters-of-2024-2/

Do it every foot or 2 for more granular precise measures

https://www.bobvila.com/articles/best-soil-moisture-meter/

Thank you. The issue is, if I understand correctly, that they are designed to measure moisture in a gardening soil, although one of the meters mentions wood and drywall. My "ground" is not a soil. It is a mix of coarse sand, rocks, and gravel. Add mostly arid climate (except in rainy season, when everything is soaking wet). I doubt there is any moisture above the leak.

[iNow]

Fair. I’m no expert on moisture meters, but I bet there’s a tool or process beyond divining rods to figure out which areas around the drain line are wettest relative to the surrounding vicinity.  

With that knowledge in hand, you could then focus your dig on a smaller section of yard. Otherwise, just redo the whole line and move on with your life. 

Edited 20 hours ago by iNow

[swansont]

If there’s a leak in the filtration system, isolating it would allow one to measure the pool level change and see if it reverted to the evaporation value, rather than probing the ground.

[Genady]

41 minutes ago, iNow said:

focus your dig on a smaller section of yard

Yep, this is the goal.

42 minutes ago, iNow said:

redo the whole line and move on with your life

Sure, but it's not time to give up yet.

18 minutes ago, swansont said:

If there’s a leak in the filtration system, isolating it would allow one to measure the pool level change and see if it reverted to the evaporation value, rather than probing the ground.

I'll do this next. Thanks.

[Genady]

17 hours ago, Genady said:

17 hours ago, swansont said:

If there’s a leak in the filtration system, isolating it would allow one to measure the pool level change and see if it reverted to the evaporation value, rather than probing the ground.

I'll do this next

I did. Shut off all the valves to and from the motor-filter assembly. No effect. Evidently, the leak is in the underground pipes.

 

18 hours ago, iNow said:

I bet there’s a tool or process beyond divining rods to figure out which areas around the drain line are wettest relative to the surrounding vicinity.  

I got an unconventional idea for such a thing. Will try tomorrow.

[iNow]

1 hour ago, Genady said:

I got an unconventional idea for such a thing. Will try tomorrow.

Unroll a package or two of paper towels across the lawn and walk across them? See where the water soaked in most?

Curious to hear your report.  

[Genady]

31 minutes ago, iNow said:

Unroll a package or two of paper towels across the lawn and walk across them? See where the water soaked in most?

Curious to hear your report.  

Below is the close-up picture of the surface texture of my "lawn". If it did not rain recently, all is dry.

Here is another:

Edited 22 minutes ago by Genady