Help with a pool leak - PLEASE!

[hal49090]

OK, not sure where to start but here goes.....I apparently have a leak in my water circulation system. I figure it's in the pressure side (no bubbles in the pump window).

Two seasons ago, one "eyeball" outlet (out of three) began blowing a little sand. The filter checked out -laterals were intact but I replaced a missing lateral screw. Last season the sand problem worsened and I plugged the offending outlet with a winterizing plug as an experiment. I figured that section of line was compromised. That cured the problem until late August, when suddenly I couldn't maintain the water level - the pool began leaking fast. The garden hose couldn't keep up with it.

My theory is that the pressure side line to the one eyeball had cracked or otherwise failed, and was now pumping water into the surrounding soil (mostly sand). Since it was late summer, I closed the pool early and deferred the problem to this season. So, now I'm looking for advice.

I have an old 20 x 40 in ground pool, I think it's called a "Hybrid". The entire bottom(deep and shallow end) is cement, the sides are fiberglass with fiberglass coping. The entire perimeter is covered by concrete sidewalk. It looks like I'm going to have to get behind the fiberglass panels to repair the tubing as a DIY project. Not looking forward to it but the few contractors I've found won't talk to me - they're too busy either opening, closing, constructing new pools, or it's the dead of winter.

I bought the house 16 years ago and the pool came with it. I don't know the actual age but I'm guessing at least 40 years. I've become a semi-expert in pool maintenance over the years, including refurbishing the bottom and sides and repainting twice (it's due for another). Past work included fiberglass crack repair with cloth and/or "bondo-hair". I feel capable of doing the work but I'm getting older and lazier.

I'm just trying to get an idea of what to expect. My idea is to cut out the fiberglass panel where the problem eyeball is located and look for the problem. At least it's in the shallow end.

Questions:

I may end up destroying one or more fiberglass panels. Are replacements available and where? Is there a substitute?

Does anyone have an idea of the most likely location of the eyeball plumbing? Would they be most likely routed close behind and along the fiberglass sides or buried deep under my concrete sidewalks?

How about anyone else with the same problem? Like to hear what was discovered and how it was repaired.

Since one line failed, other sections may also soon follow. Is there another way - like replacing the entire pressure side plumbing with some sort of above-ground substitute?

I'm in SW Michigan. As I write this, there is at least a foot of snow remaining and the temp hasn't been above freezing for weeks. So, I have some time to plan an approach.

Any advice or personal experience will be appreciated.

 

[JasonLion]

How low did the water level go as the pool leaked down? That is an important clue, as the draining will stop at the level of the leak. That doesn't pinpoint a location, but it does narrow things down a lot. Another thing that can help narrow down the leak location is to inspect the pipes from the inside with a fiber optic camera. That will get you distance and the general heading of the leak, which could save you a tremendous amount of digging.

Plumbing normally runs along the walls most of the way, turning off toward the equipment pad at some point (usually very near the closest point on the pool to the pad). It won't be right against the walls. Usually parallel to the walls but several inches to a foot away. There are other ways to do it, so you can't be 100% sure, but that approach is very very common. I've seen plumbing run straight line to the pad, even if that means going under the pool rather the run around the sides, but that is much less common.

If the leak is indeed along the walls this is going to be a very difficult project. Replacing panels and getting a good seal between panels is difficult at best. Tunneling under the deck has some significant advantages, though that is also going to be difficult given the width of your deck. This isn't going to be an easy fix. Expect it to take time and lots of effort.

 

[hal49090]

Thanks for the input. I have ordered an endoscope (actually pretty cheap @ under $30). Hopefully it will find the problem area and a general location.

As to the water level - It never stopped dropping until it reached the concrete. I think it may have slowed down in the neighborhood of the eyeballs but that's when I closed it up (with the usual winterizing steps), and quit paying attention. My pool has always been a bit "porous" but I'm almost never able to visually find any suspect leak areas. I have one of those automatic fillers (works like a toilet valve), and it maintains the water level quite well - until the sudden leak episode. However, it did run more than I like.

BTW, I inspected and recaulked the pool light at the start of last season.

This is a pool owners nightmare - a sudden loss of pool water for an (apparent) unknown reason. I see $$ signs flying away.

I still have a mountain of snow that needs to melt before I can get started. Meanwhile - additional postings are welcome.

 

[swimcmp]

Hal you are correct in having a "hybrid". Those pools were pretty common in some areas mid 70s into the 80s. That being said if you damage a wall panel there is not an economical way to fix it. The fiberglass wall panel goes into the concrete for at least 6". That creates the water stop, I have built several pools in a similar manner. If your plumbing has cracked under the deck most likely it wouldn't draw sand into the pipe and shoot it out the return. If the pool leaked down to the floor seam with the wall I would be more suspicious of a hydrostatic relief valve in the main drain if you have a main drain. Once you capped off the returns for winter you eliminated the plumbing from the return side as your problem if it continued to leak.

The other possibility is the main drain plumbing. From past experience it won't necessarily draw air in. It is possible for a drain line to leak and not pull air. Depends on how good the design was for the plumbing. Also could depend on the amount of ground water around the pool as the problem could be in water and not letting air get into it.

 

[hal49090]

To swmcmp:

Thanks, I need all the input I can get. At this point, it's all speculation cause I don't want to work in the snow.

My thoughts: only one return line (out of 3) actually blew sand - evidenced by a fan shaped pattern on the pool bottom. And when I plugged that particular return during the season, the sand problem stopped. My big leak occurred 6-8 weeks later.

I certainly hope I don't have a main drain issue, but if I did, it seems to me that the main drain and skimmer return both go thru my filter before being returning to the pool. That should remove any sand picked up in the main. That assumes my filter is working properly. I have another older thread detailing those efforts. I'm reasonably sure the filter is OK.

Here's my tentative plan so far: when weather permits. I will inspect the "sandy" eyeball outlet with my new endoscope (arrived yesterday), . Hopefully I will see and learn something. If not, I'm SOL and back to square one.

The best scenario I can hope for is to find a break in the line close behind the eyeball. If so, I plan to neatly saw and remove a section of the panel for access, repair the line, then replace the panel section with fiberglass cloth and epoxy followed by epoxy paint.

In any case, as a contribution to pool owners on this site, I will inform readers of what I find and problems encountered.

 

[swimcmp]

Cut concrete not panel. Concrete is easier to refinish. Trying to dig in sideways to get to the plumbing is much tougher and very risky since the material overhead could collapse onto you.

 

[hal49090]

FIXED IT!!!

Original poster here - My idea of using an endoscope failed. The sand in the return line kept building up in front of the lens preventing any decent view. I ended up paying a well-known company to find my leak(s). They found 3 problem areas - had 2 in the "eyeball" areas caused by tree roots that had actually grown between the pool wall and the tubing. This actually forced the plumbing away from the fitting. The major leak was an actual break in one of the return lines. I suspect this was caused by some sort of upheaval or shifting over the years - probably before I owned the place. Apparently started as a small crack that finally let go (Photo below).

In any case, I was amazed that the leak detection outfit found it so easily and accurately. They marked the spot and sure enough, it was dead center.

In spite of my do it yourself mentality, the job was too much for me alone - too much concrete sawing, pounding and digging given my arthritis and age (not to mention no experience in this type of repair). I hired it out to a crew recommended by the leak detection people. I did, however, repaint the entire thing myself after they were finished.

So far, I'm thrilled with the results. I finally got the thing filled around the middle of July (2-1/2 days filling with the garden hose). I had two cloudburst-type rains over the following week - actually had to pump water out - the level went above the skimmer. Never, in the last 15 years, did I have to do that. The automatic pool leveler has not turned on since I hooked it up.

The photo is of the bottom of the hole showing the return line with the major problem