Need Help And Ideas On Source Of A Strange Water Loss

coollx · Postby **coollx** » Sun 31 Jul, 2011 14:08

I have a 15,000 gallon inground pool with a 15 year old vinyl liner. Beginning about five or six years ago we started to experience some small leaks on the pool floor all pretty much near where the walk-in steps meet the floor. I've assumed this is normal with vinyl lined pools and their repair is a cost of ownership.

It's been very hot and dry where I live this month so I assumed the drop in water level (4" over about 3 weeks) was a result of normal evaporation. So I had a local person deliver water the other day to bring the water level up as high as possible. Well a strange thing happened. The water (1,800 gals) was added at 1:00PM and by 4:30PM the same day the water level dropped one inch. So I measured the water level again the next morning and it was at the same reduced level. Then, the following day we finally got about 3/4" of rain which should have brought the water level up but it didn't. It was at the same point. A few more hot days passed with no rain and the water level dropped about 1/2" which is more than normal so I had a diver who does liner repair I've used before come over. I explained what had transpired and said because of the large sudden water lose when I had water added, I suggested the problem might be high on the sides of the liner.

He checked everything and found and repaired 3 small leaks on the liner floor but nothing up high. He said he wasn't sure where all the water initially went? I sure would have felt better if he found a hole, split or separation up high on the sides of the liner. He did ask if I knew whether I had some type of valve in the skimmer that prevented the water from rising above a certain height. I said I didn't know, but such as valve would certainly be a plausible explanation for losing that much water in 3 1/2 hours.

I think it's probably time to replace my liner because of its age and it will likely be very susceptible to constant leaking, but I'd sure like to first find a logical explanation for the sudden 1" drop in water level the day I had water added. By the way, the water level in the pool has been at and stayed at the high initial water level...which is usually about where it is in the spring when all the snow melts and we open the pool. This is really baffling.

I would appreciate any thoughts and ideas before I have the liner replaced in the event other areas need to be checked or tested first.

Thank you.

Postby **ChuckGeo** » Wed 03 Aug, 2011 18:10

If the pool was filled higher than 1/2 way up the skimmer face plate you might have lost the water from somewhere in the top half of the skimmer throat or the top of the skimmer body. Another possibility is a leak high in the light conduit.

coollx · Postby **coollx** » Thu 04 Aug, 2011 12:32

I do not have a light but the water was filled to the very top edge of the face plate surrounding the skimmer opening.

Is there something built into the skimmer design that will dump water above a certain height? If so, is it something I should be able to see in order to confirm that's what did it?

Thanks

Postby **ChuckGeo** » Fri 05 Aug, 2011 05:08

I'm not aware of any skimmer that comes with an overflow port built in, however I have seen some installed mby the pool installer. Usually it''s just a pipe installed through the top portion of the skimmer. How much does the water level drop in 24 hours from it's normal level (1/2 way up on the skimmer faceplate)? Does it loose the same whether the pump is on or off?

coollx · Postby **coollx** » Fri 05 Aug, 2011 16:42

Currently, my water level in the pool drops between 1/8" and 3/16" per day. It doesn't seem to matter whether the pump is on or not.

I raised my question initially because the pool mysteriously dropped by one inch in 3 1/2 hours the day I had water delivered last week. However, I did have the water brought up to the top of the face plate surrounding the skimmer opening.

It just seems as though something quickly drained off water because once it was down to that reduced level its been dropping about 1/8" to 3/16" per day which I'm presuming is normal evaporation?

Thank you

Postby **ChuckGeo** » Mon 08 Aug, 2011 05:59

It sounds as though the water might have leaked out through the back, top of the skimmer faceplate, a crack in the top, side of the skimmer throat or a crack in the skimmer body.
I'm encouraged that your loss with the water at normal level is 1/8" to 3/16" per day. Here in Atlanta we've been loosing that, or a little more, on a 95 degree day.