Evaporation or leak?


Silver Supporter
Aug 7, 2009
Bloomington, IL
I have a question about water evaporation in a pool covered with an automatic cover. I have an opaque cover. The entire surface of the pool is covered. During a 24-hour period, does water evaporation occur? If so, how much should I expect? My water temp is in the low-80s. Air temp is low in the low-80s. Even on a sunny day with the pool completely covered, should I lose any water to evaporation? I’m losing about 1/16 of an inch now. Not much on a daily basis, but it adds up over time. I’m trying to determine if I have a slight leak or not.

Thanks for the help.


Jun 9, 2010
Take a clear container, put it on the top step and fill it with water to the level in the pool. If the level in the container drops at the same rate as the level in the pool, the water loss is due to evaporation. If the pool water level drops below the level in the container, the loss is due to another cause such as a leak, splash out, huge thirsty dog :-D , etc.