I have had a leak somewhere in my pool plumbing for a while; just hadn't been that bad until recently. I suspected suction side, as most of the time it seemed to lose more water when the pump was not running. Well, about a month and a half ago, it got bigger; was dropping 2-3 inches per day, with or without pump running. Also sucking a lot of air into the pump and not able to build and maintain normal pressure. Called a leak detection company, but they had about a 3 week backlog, so I ended up shutting off the pump and letting it sit to see how far it would drop. The water level dropped steadily to about a foot below the skimmer opening. Next step was to inspect the pool shell (fiberglass) at that level; did not see anything. Next, I added back a couple inches of water and did the dye/syringe test around the perimeter at the level it stopped dropping, and did not see any motion. Also did dye test around the main drain the best I could, also could not see any flow towards the main drain.
So, since leak detection company needed pool full to normal level, I capped the port in the skimmer basket and refilled. I also ran an above ground suction line to be able to filter the water, etc. This worked great, with the pump no longer sucking air and building proper pressure. Seemed to further confirm a suction side leak. Over the next 2+ weeks waiting for the leak detection company, water level held steady (probably a couple inches lower than I should have put it, as they were forecasting heavy rains that didn't come; 1/3 of the way up skimmer opening rather than the 2/3 I normally try to run...).
Leak detection company came yesterday and did acoustic search, dye test around all inlets/outlets, and pressure test on suction and return lines (except main drain) which were all ok. They also were able to scuba down to the main drain to do the dye test much more effectively that I had been able to. They were unable to do the pressure test on the main drain, though, as they could not get a pressure plug in it due to the fitting in the photo. They believe it is glued in, and they would need to drain the pool and cut it out to test it, at which point I would just have them cap the pipe and patch the wall of the pool leaving just the skimmer anyway, I think. My preference would be to just plug it as is...
My questions are, does all of this serve to confirm the problem is in the main drain suction line? Or is there anywhere else I should look? And, is anyone familiar with the fitting in the photo? To me, it looks like it was probably caulked in place and threads in like the eyeballs in the returns. If so, is there a chance it could be removed and capped there? I'd prefer not to have to drain the pool quite yet; it will likely have to happen soon to have it resurfaced anyway, and could cut/patch at that point, but would like to get it operational without the above-ground line for the rest of the season if possible...
Thank you for your feedback!
So, since leak detection company needed pool full to normal level, I capped the port in the skimmer basket and refilled. I also ran an above ground suction line to be able to filter the water, etc. This worked great, with the pump no longer sucking air and building proper pressure. Seemed to further confirm a suction side leak. Over the next 2+ weeks waiting for the leak detection company, water level held steady (probably a couple inches lower than I should have put it, as they were forecasting heavy rains that didn't come; 1/3 of the way up skimmer opening rather than the 2/3 I normally try to run...).
Leak detection company came yesterday and did acoustic search, dye test around all inlets/outlets, and pressure test on suction and return lines (except main drain) which were all ok. They also were able to scuba down to the main drain to do the dye test much more effectively that I had been able to. They were unable to do the pressure test on the main drain, though, as they could not get a pressure plug in it due to the fitting in the photo. They believe it is glued in, and they would need to drain the pool and cut it out to test it, at which point I would just have them cap the pipe and patch the wall of the pool leaving just the skimmer anyway, I think. My preference would be to just plug it as is...
My questions are, does all of this serve to confirm the problem is in the main drain suction line? Or is there anywhere else I should look? And, is anyone familiar with the fitting in the photo? To me, it looks like it was probably caulked in place and threads in like the eyeballs in the returns. If so, is there a chance it could be removed and capped there? I'd prefer not to have to drain the pool quite yet; it will likely have to happen soon to have it resurfaced anyway, and could cut/patch at that point, but would like to get it operational without the above-ground line for the rest of the season if possible...
Thank you for your feedback!
