Leaking Like A Sieve

[flatlander]

I have an older (mid 60's built) in-ground pool it has a cement finish (possibly gunite I don't really know the difference) in the basin with 12 inches of 1"x1" tiles around the top of the basin. This is about even with where the skimmer is.

For the last few years I have been losing more water than I should through normal splashing and evaporation. It started out as 1-2 inches a week and is now about 6-8 inches every 36 hours - We can't go away for a weekend or else the level drops to the point that we lose prime. I have done a number of tests including evaporation, pressure and even running intake and out let lines overland.

Last fall when I was shutting the pool down for the season I flipped the pump breaker and let the pool sit for few days. The level dropped to just below the skimmer and held at that point for a couple weeks. I had to use a pump to finish draining the water to the level where we leave it for the winter.

This spring I was advised to dig below the skimmer to see if there was a fitting loose or pipe cracked. I have cut the cement decking and dug about 24 inches (to a point just below where the skimmer return line elbows to the pumphouse.) I filled the pump, return line and skimmer. My water level in the basin was still a good 18 inches lower below the outlets. The water level in the pump/line/skimmer remained the same for several days. There was not even a sweat on the fittings/line that was exposed. The clay in the hole I dug dried out fairly well.

I was then told to fill the pool to the normal level to see what happens - and here is where things get interesting...

I could see the water weeping through the dirt into the hole (not coming from the skimmer/pipe) almost as soon as the water started hitting the tiles. In about an hour the hole was filled and by the next morning the water level dropped to below the skimmer again. There is about 2-3 inches of tiles below the skimmer and as soon as the level hit the last tile the draining stopped.

Overall the tiles seem to be in pretty good shape and the grout seems to be solid. One problem area is the tiles ontop (coping) of the deck between the pool edge and cement decking. There are a couple areas around the pool where the tiles have lifted. Last year I took the loose ones out and fixed the area with a "stonehard" type product. My patches seem to have wintered well but I am noticing another area of deck tiles lifting across from the original problem spot.

I checked around with the pool shops and tile companies and it was suggested perhaps the grout around the tiles needed to be resealed - since it is a fairly cheap easy fix I tried it. I also used some premixed over the counter grout from the hardware store to fill in a couple areas where I thought there was less grout than there should have been. One of these areas is at the mouth of the skimmer - I regrouted the entire opening of the skimmer.

I refilled the pool to the normal level and while the hole behind the skimmer has filled up it does seem like it is at a slower rate. The water level also seems to be dropping but perhaps at a slower pace.

I am close to making the decision and start knocking the whole thing out. Does anyone have any suggestions of what the problem may be or what other options I have to keep this pool running?

Thanks

[Pool Clown]

check the light conduit as well. The conduit normally runs up to a point about 18 below grade then runs over to where the j-box for the light is, the conduit makes a 90 and goes vertical to meet with the j-box. The conduit is normally flooded with pool water and if the conduit has a bad joint or a joint that has failed, the pool will leak down to where the leak in the conduit is. Could be right at the sweep 90 right below the j-box.

[USMC_Wifey_1345]

My pool guy told me that if we loose water -- more then an ince every 24 hours -- that there is a break in the line of the return. If it were the intake, we would loose prime that is how you know it's the return. Good luck!

[flatlander]

Thanks for the advice but there is no pool lights and I've already ruled out the lines with pressure testing. I was still not convinced so last year I plugged all in-ground lines and ran alternate lines overland and still lost the same amount.

The leaking seems to have slowed since if filled the pool yesterday but I did lose about 1/2" overnight.

I am narrowing it down to one of three problems - grout/tile related, a leak around the skimmer opening (between the tiles and the actual skimmer) simply because this is the area that I have open and can see the water leaching through the dirt or a fatal crack around the ring of the basin at about the bottom of the tile.

Any thoughts???

Thanks

[Pool Clown]

I think you are on the right track. Carry on.

[Pool-newb]

Sounds logical to me;

- You've fixed one area and the leak slowed.

- You see another area that is damaged.

So the first fix did change something and there is another area that could be fixed?

I would fix the 2nd area and consider redoing all the tiling - maybe even letting someone professional do it. It sounds like the grout and tile glue has finally reached an age where it is failing and will keep on failing in sections until you've patched it all - and then maybe your patches will start failing.

Let us know how it works out!

[Wobbly]

This site seems to have pretty good leak finding advice: http://www.poolrepair.com/archive/leaks.html