my pool loses alot of water over the winter

[schnitzjr]

OK, so I have a mysterious problem with my above ground 18x33 oval pool that has me baffled.

5 years ago I covered my pool and it immediately started losing water. I mean, a foot a week.
My brother-in-law spent 30 minutes in 55 degree water under the pool cover looking for a leak but found nothing.
In the Spring i drained the foot of water left and paid for a new liner.
The liner installation crew found the liner was in perfect shape and saw no evidence of nearly 16,000 gallons of water leaving the pool. NO washout-nothing.

So now I have my new liner.
Winter comes along, cover pool and once again, pool starts losing water. I spend the entire winter running a hose and making sure my pool doesn't collapse.

Last year, I installed a brand new cover and again, within 3-4 weeks lost all the water. I almost lost the pool as one side actually cave in but thankfully it was from the top so once filled the wall worked fine.

This year, I spnt waaay too much money on the second best cover Island Wreck has to offer. I cover pool and for a week it's fine but going into the second week I see my air pillow slowly disappearing below the top ledge of the pool.
It's losing water as we speak.

Now, I understand it *Could* leak from the skimmer but the water level has dropped below so it no longer can.

I am baffled and don't know what to do. I'm a replacement liner and 5 pool covers into this problem.

 

[mknauss]

Welcome to the forum! Sounds like an interesting problem ---

What outlets are there in the pool walls or floor? Could one be siphoning out water?

The water has to go somewhere. And evaporation does not seem plausible.

Take care.

 

[Teald024]

Sounds like a confusing problem. I'm with Marty on this one. Do you have floor drains? Do you disconnect your equipment? How about a picture of your setup?

If the water is leaking that quickly, you should notice water on the ground or icy spots when it's freezing out. Usually you can let it drain and then when it stops draining, that is the level of the leak. If it never stops draining, then the hole / leak is in the bottom. What you are describing doesn't come from a small hole and I would think it would be fairly noticeable. Your 1 ft drop / week is: 3900 gal/week, 557 gal/day, 23 gal/hr, 0.39 gal/min, 6.2 oz/min.

 

[Teald024]

double post

 

[schnitzjr]

Yep, you would think there is a gaping hole at the botom of the pool but nothing. Plus, the pool holds water until I cover it.
It will drain until aprox 1' is left on the bottom.

 

[ta2dwonderwoman]

do you leave the hose in the pool after you fill and turn it off? that will create a siphon and that will suck your water till the ground back at the source is too wet to take any more...happened to me earlier this year and that was the culprit...

 

[JoeSelf]

Are you draining water off the cover? If it has holes, water could seep thru and then get drained off.

 

[mknauss]

So here is one out of the box.

Your cover is situated as the middle is the high point with your pillow. When the sun hits the cover, it warms the air below it and then when the sun goes down there is condensation on the cover (pool side) that runs down the cover and outside the pool. Now how you can get as much loss as you state with this theory, is beyond me. It also would stop once it gets cold enough to freeze the water under the cover.

The mystery continues .....

 

[Teald024]

Yep, you would think there is a gaping hole at the botom of the pool but nothing. Plus, the pool holds water until I cover it.
It will drain until aprox 1' is left on the bottom.

You have no magic cover. if it only does it when the cover is on it, then that covering process or closing method is causing your issues. do you normally have water on top of the cover to hold it in place?

can you explicitly describe your closing process, What steps do you perform and how?

Do you have a main drain at the bottom of the pool?

And you say that this ONLY happens when the pool is covered with the winter cover?

How about a picture of your pool. and another of the skimmer return area.

 

[weird_tolkienish_f]

A hole in your cover will make it seem like you are losing water, if you are continually pumping it out.