Still chasing leaks... any other options to consider before digging out and replacing lines?

DoubleJ

Member
Jul 10, 2018
11
Canterbury, New Hampshire
We've been fighting leaks since year 2 with our pool (currently in year 3) and I'm now suspecting poor winterizing has led to leaks in our suction lines.

Current loss rates are approximately:
Without pump running: 0.25" per day
With pump running 8hr/day: 0.5" - 1" per day
With pump running 24hr/day: 1.5"+ per day

Our loss rates appear to be steeper when we're drawing more from the skimmer line than the bottom drain. We're a good 8-10 inches below the skimmer now, so it'll be a while before we're out of bottom-drain-only mode.

Potential causes that we've eliminated/fixed:
1) We had a couple tears in the liner from installing the ladder without using the rubber caps 🤦‍♂️ - a liner patch kits appears to have resolved this and the wall behind the liner is no longer spongy. I've performed the food coloring test and nothing is pulled through. I've gone across the whole liner and can't find any other potential leaks there. It looks to be in good shape.
2) Our spider gasket and ultimately multiport valve needed to be replaced last year (big Thank You for assisting with this here: Water leak - malfunctioning valve? ) - I've confirmed that we're not getting any leakage out the waste line anymore.

When our pump is not running, we can hear air bubbling and escaping every few seconds. This seems like it would be consistent with a leak in the suction lines.

We've tried using the product "Fix-a-Leak" but admittedly it calls for applying back pressure to the suction lines in order to treat them, and I have no idea how one would do that.

I'm wondering if our next course of action is to dig up our suction lines and replace them, but first I'm curious if anyone has any suggestions around:
1) How to apply back pressure to the suction lines for one more attempt with "Fix-a-Leak"
2) Any other potential leak sources we should investigate
3) Any other steps we can take to confirm that a problem exists in our suction lines.
 

DoubleJ

Member
Jul 10, 2018
11
Canterbury, New Hampshire
That would be great; why do you say that?

If I'm sure that there's nothing leaking with the valve or the filter, I guess that just leaves the return lines or something I missed in the vinyl?

I worry about problems with the suction lines because both times I've closed the pool for the winter, I've:
- Blown out the return lines, then sealed off, then added antifreeze
- Added antifreeze directly to the skimmer drain, then screwed in a Gizmo
- Never added antifreeze back down the suction line to the bottom drain

Although I suppose if I've correctly winterized the skimmer drain but incorrectly winterized the bottom drain, our symptoms might be slightly different - with more problems around the bottom drain and fewer problems around the skimmer.