This week has been basically sunny,,windy with temps 60's to 70's. I noticed I was loosing more water level than normal. I measured today ( very un-scientific I know) by placing waterproof tape at very top of water level last night then measured to water level today. I came up with a loss of 1/2 to 9/16 max loss. Is this within limits considering windy weather and sunshine ?? I know it's sorta "anal" by me but I'm a stickler when it comes to our pool !.. Pool is 5 years old.... I got lucky in finding this site a few months after it was up and running,, Last 4 years maintenance duties have become routine and easy, just the way I like it!