Inground Pool Leak - Main Drain?

[rhinebeckdude]

I had noticed a loss of water for last two seasons, and noticably last Winter where I lost almost 3 feet of water. So, this past Summer I had the Man out to find and fix the leak, the one he found on the bottom slope seem to be too small to be the real problem, but I'm not the expert. So, now 6 mos later, I'm still seeing water loss with the pool closed up...probably several inchs a week. So, I'm guessing I have a main drain problem as the water is below the return lines and the Man didn't find any other leaks around the pool.

So, with the water level lower, I can try and get a dye test to see if somethiing gets drawn into the main drain. then I can try and cover the drain to plug it and see if level doesn't drop. I see that fix-a-leak can be applied though not sure how effective it would be getting to the actual leak without and suction on the line. And, I see we can choose to plug the main drain.

Curious what comments the community has as I look to open the pool in the next 30 days.

[bob8619]

You say "still seeing water loss" so do you mean it never stopped after the guy came out to fix it or are you saying its now leaking again?

[rhinebeckdude]

No, the leak didn't stop, likely that I had 2 and only patched the one which again looked to small to cover the amount of water loss. I guess I will try and plug the main drain and see if the affects it.

[Beachbreeze]

I've tried the fix a leak and it was just a waste of money. I had a main drain leak for over a year and finally decided to check the line. I started digging down at the filter and when I got to the first elbow I noticed it was off and never been glued on. To find other leaks I fill the pool and keep an eye on the level until it stops going down and mark it with duct tape. That will give you an idea where the leak may be. If there are no cracks at that level, it may well be in your in one of your lines. Check around the skimmer inside the pool. A lot of time the plaster does not stick or falls off where it connects to the plastic skimmer. If so, I've had good luck just caulking it and it stopped the leak. You may also want to check behind the light if you have one in the pool.

[rhinebeckdude]

BeachBreeze, your ideas won't apply here as last Winter the level in the pool was well below the pool light and skimmer lines (2 feet or more) and likely below the level of where the pipes emerge for the filter area. The only logical conclusion I have, given that the leak specialist only found the small hole last Fall, is that they leak is either around the main floor drain or on the piping returning the main drain to the filter.

I've been focused on keeping the pool clean and with the tons of water this past 2 mos the level hasn't been an issue until just this week again where I have started to use the hose to maintain water levels above the skimmer/return lines.

I got the fins and mask to check out the main drain and try to plug it, I just don't have the breath-holding capacity ....yet.

[brettnolan]

I assume this is a concrete/gunite pool? Then again, what was "patched" on the slope?

Does the leak ever STOP at a certain level? If so, where? And what potential leak areas are there below that (cracks, drains, lights)?

If you have a leak in the main drain, of the size you indicate, you would probably have a ton of air in your pump (if it would prime at all), when the skimmers are closed and you are only running on the main drain. This is not always the case however, sometimes there is enough water in the ground to keep that from happening, in which case...

Main drain line breaks are fairly UNcommon. If your pool has a hyrdrostatic relief valve, it is most likely that.

btw - if used properly (follow the instructions on the bottle to a T), fix-a-leak WILL work on smaller leaks. Not on something 6 inches per day.