Unidentified Leak - When to take action?

[oh_me_oh_my]

After increasing need of topping up our pool, we reached the point where we have to acknowledge we have a leak. This has been confirmed at 1/8 to 1/4 inch a day (evaporation is not a factor, solar cover is on and pool is indoors).

When we were losing less than an inch a week, it wasn't too concerning (and could easily have been evaporation), but now that we lose a little more, at some point we'll probably have to get help to find it.

What we have done so far:

- using a mask, a weight to hold on to, and food colouring, checked likely suspects - light, surface cracks, skimmer, main drain (nothing found)
- let the water drain down below the skimmer opening. The water has just fallen below - it's now 1/8 below the skimmer opening on the pool side, but in the skimmer, still full (this seems like confirmation that it's not the skimmer)
- water loss seems the same with the pump on vs. off (not confirmed - planning to do so).

So, I'm realizing I probably need to call in a leak detection company - but is it severe enough yet that a) it's warranted and b) they can find it? At this pace the water is falling too slowly to just wait to see where it stops.

My last step will be to dive down and plug the main drain, as well as the return, just to be sure it's not those. We have no hydrostatic valve in the drain.

Summing up, three questions:

1) Is it severe enough that I should call somebody in?
2) Will they be able to find it, at the current leak rate?
3) Did I miss anything obvious?

Thanks for the help!

 

[bobodaclown]

Sounds like you're taking the appropriate steps. Are you currently using the pool? You could just let it continue draining down, till it stops. That would be where the leak is. Seems like it's not at the skimmer, that leaves returns or main drain.
Did you do the bucket test to confirm it is not evaporation? I would have sworn I had a leak, turned out to be evaporation.

 

[oh_me_oh_my]

We tend to use the pool daily... not in the last two weeks due to cold and flu season though, so we let it go down.

I did let it go down without refilling for 2 weeks, and it went down a total of 3 to 4 inches. It was 1/2 below the skimmer when we decided to top it back up again (hoping to be healthy enough to get in again soon).

Being indoors, and covered when we don't use it, the evaporation loss is very predictable. When it fell below the skimmer, the skimmer lost no water at all, but the pool still continued to go down at the observed rate - kind of an in-place bucket test, where the skimmer is the bucket. My initial suspicion was the skimmer, and that completely contradicted it - I was really surprised at how steady the water level stayed in the skimmer.

I will try an actual bucket to confirm, I don't want to call a company out only to find out I was jumping the gun. I'm also still going to try plugging all the plumbing (including the main drain) when my ears clear from this cold I have and I can properly equalize when I'm on the bottom of the deep end.

Thanks for your help!

 

[duraleigh]

1) Is it severe enough that I should call somebody in?
2) Will they be able to find it, at the current leak rate?
3) Did I miss anything obvious?

1. Not really, but it will probably drive you crazy until it's fixed.

2. I have no idea.

3. Why can't you let it leak down until it stops?

 

[oh_me_oh_my]

1. Not really, but it will probably drive you crazy until it's fixed.

Absolutely!

3. Why can't you let it leak down until it stops?

Pride, using the pool daily (when healthy), and impatience

It was oddly saddening to look into the pool enclosure and see it below the skimmer. At 2 inches a week, it would be several weeks before we even hit the top of the light.

 

[needsajet]

If you want to hasten the testing, you could pump it down to a couple of inches above the light (assuming that's the next lowest opening in the shell), and see if it keeps going down.

 

[oh_me_oh_my]

If you want to hasten the testing, you could pump it down to a couple of inches above the light (assuming that's the next lowest opening in the shell), and see if it keeps going down.

Great point, will wait until that won't cause a skating rink outside and may try that. In the meantime, I'm predicting a lot of time with a mask on and some food colouring... which is actually surprisingly enjoyable.

 

[needsajet]

If you want to do it sooner and/or avoid the outdoor mess, put the drain line into a laundry tub or floor drain in a bathroom or laundry room. Check local rules

 

[cmc8]

Sorry to hijack this thread.

I'm in exactly thr same situation..indoor pool in near Toronto with slow leak (i suspect, not confirmed)...was wondering what you did to fix this. I was advise to try fix-a-leak but have not done so. Will do bucket test....
I was going to message you instead of hijacking but i couldn't figure how to directly to so.

Thx