Leak- Losing 3" a day

[ellry99]

Thanks for the replies.

The pool leaks when it is running and when it is not. It is leaking faster when it is not running.

I kept it off for a 48 hours and it leaked down to the returns and then I filled it back up to run it off the main drain to keep it from getting too dirty. So I don't know if it would have leaked further than that.

No leak at waste line.

I haven't had any work done recently. Had a tile and coping job 2 years ago. Everything fine after.

However, I have had the spa return start bubbling when pool is off, like it was sucking water in. However, when I did the dye test, it did not suck the dye in thru that return.

The sand filter is higher than pool and is 2 year old Hayward.

I did have a crack in my skimmer when I opened my pool. I sealed it with marine putty and I don't think that is it as it is way above where it is leaking down to.

My pool is about 30 years old.

Anything further I should test?

[JohnT]

Usually a leak that is worse when the pump is off is a suction side leak, like a cracked pipe from a skimmer or drain. When the pump runs, it pulls the gap together and slows down the leak. It would have to be below the water level to behave this way. A typical pressure side leak gets worse when the pump is on. A typical pool structure leak doesn't care whether the pump is on or not.

Plugging the skimmer and leaving it off would be my next step. Good luck.

[Poconos]

Elle,
You've gotten good advice so far. Seems like things are pointing to the main drain. When I was looking for my leak last year I taped a piece of small diameter auto vacuum hose to a 10' PVC pipe, 1/2", and used that to squirt dye at the deep end. Used a 1 gal. garden sprayer for the dye. Water has to be very still and you need to squirt just a little bit and watch. 3" a day in my pool was about 3 quarts per minute which is easy to find. For dye you can get a dye marker at a dive shop, or boil chopped beets.
Al

[ellry99]

Yes, I fear it is the main drain that is leaking.

I plugged all the returns in pool and spa. (The water level was already below the skimmers) and the level went down another couple inches over night.

Is the main drain a major repair? What is involved in the repair? Do I have to drain all the water out of the pool?

[Poconos]

Someone else can chime in because I have no idea. Anything buried can be a real PITA, translated...$$$$. Personally I wouldn't want one. I'd still do a dye test just to confirm.
Al

[ellry99]

So.. I am losing waaaay more than 3" a day. I lost over 12" in the last 24 hours. The water is now 1/2 way down the light.

I am letting the water go down to see if it will stop after the light, and if not guess its the main drain. I guess I wouldn't be losing this much if it was the light.

I did the dye test around the light and nothing. I tried to do it on the main drain, but I need to get a longer pipe. My wasn't long enough to get close.

[ellry99]

I had a pool guy out today.

He said I am losing water so fast (8-12" /day) he thinks that the hydrostatic plug rather than a leak in a pipe/drain. My water level is down about 4 feet. He thinks the hydrostatic plug may be stuck open that a normal leak wouldn't be so fast. He also said main drain leaks are usually as low as mine has gone.

Does this make sense as a possiblity?