Why is my pool losing water only in cooler months?

Henry121083

Silver Supporter
Aug 10, 2018
101
Newtown
Hi All,

I live in CT - have a 25K in ground with raised spa that overflows into the pool. We opened the pool in April and have been good on water level up until about 3-4 weeks ago.

Same thing happened last year - as the weather got cooler, I keep having to add water to the pool.

I add about 1.5 to 2" of water every other week- (attached is a pic of my pool to give an idea) the shallow end is about 4 ft and deep end about 8ft.

Any ideas as to why this happens? Since we've opened the pool I've only had to add water about 3 weeks ago which has me ruling out a leak

Also, I have not been using the heater for the spa or pool - we haven't even been using it the last month.

Thanks for any and all input
 

Attachments

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
16,024
Northern NJ
Evaporation. Warm water with cold night air increases evaporation. On a very cold morning you will see fog rising from the pool.
 

Henry121083

Silver Supporter
Aug 10, 2018
101
Newtown
Evaporation. Warm water with cold night air increases evaporation. On a very cold morning you will see fog rising from the pool.
second dumb question - any way to slow evaporation down? I'm going to run my well (and my pocket because i have to keep treating the water) dry lol
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
26,617
Laughlin, NV
Cover the pool. That will stop evaporation.

I lose 1/2" to 3/4" a day. The greatest evaporation rate is in May and Sept/Oct, when our pool water warms to upper 80's during the day and overnight air temps drop into the 70's. With very low humidity.