Lost a few feet of water over winter

maf528

Member
May 16, 2017
15
Marlton, NJ
Just opened our pool today and the level is 3 or 4 feet lower than where we left it. Well below any plumbing, aside from the main drain. No visible cracks that I could see either. Is there definitely a leak in the main drain or could that much evap? Is it worth filing a little to see if it holds or just have some pressure test the drain?
 

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ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
8,880
Northern NJ
You lost even more water than 3 or 4 feet because we had a very wet winter and everyone was draining their pools to keep them from overflowing after having been lowered.

One of the things you can easily have checked with the pool at that level is the hydrostatic pressure relief valve that may be in the main drain.



 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
8,880
Northern NJ
I've added about a foot of water, did the bucket test and didn't lose anything. Does that make any sense?
What period of time did you lose the foot of water?

How were conditions different between when you lost the water and the bucket test?

How long did you do the bucket test for?
 

maf528

Member
May 16, 2017
15
Marlton, NJ
I lost the water (3+ feet) between October and April while the pool was covered. Then added about a foot back this week. Bucket test was this week, for 2 days.
 

AndyTN

Bronze Supporter
Mar 27, 2019
141
Memphis
I have a vinyl liner so this may be different but 2 years ago, I had a small hole in my liner. When we had dry conditions for a few weeks, we would be losing a 5-6 inches of water per week and I would fill it back up each week. Later in FEB after a few weeks of heavy rain, the water level wasn't dropping so I though the problem resolved itself.... It turns out there was a small hole and the ground water level during the rainy weeks was "supporting" my pool water and keeping it from leaking. I patched it in the spring.

No clue about the weather conditions in NJ the past couple months but as Allen is pointing out, the different weather conditions could change how quickly water leaks and losing several feet of water over winter is some sort of leak. You aren't losing water due to evaporation in the winter with a cover.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
8,880
Northern NJ
I lost the water (3+ feet) between October and April while the pool was covered. Then added about a foot back this week. Bucket test was this week, for 2 days.
So that says the leak is above the water level you tried the bucket test at. That seems to say the leak is not in your main drain.

Fill the pool to normal water height and then leave the bucket in and see what happens.
 

Catanzaro

Platinum Supporter
TFP Guide
Jul 30, 2014
3,322
Monmouth County, New Jersey
I have a solid cover. This winter, for some strange reason, I pumped water off over a few weeks, cover sank and water level was under the return or near there. Immediately I thought that water was lost through a tear, etc., or pin holes on top of the cover. Quickly filled it up and upon opening the pool water was pumped from the top to the bottom. Kept tabs on level. No water loss.

Here are my thoughts. Evaporation through the winter because of varying air/water temperatures. Heavy winds that evaporate water quickly. Only logical explanations as I am barely losing water through evaporation and pool has been opened for over one month. Thanks!
 
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