Evaporation cover that *doesn't* raise water temps..?

BuckeyeChris

Well-known member
Jan 28, 2014
820
Buckeye AZ
I've committed to building some pvc frame 4.5x4.5' cover squares we can toss on the pool when not in use. Evaporation is accelerating total pool water replacement due to either fill water with high calcium, or fill water post-softener that increases salt.

The solar covers available to trim down all advertise as solar covers that will increase water temperature. This is NOT what we want all summer in Phoenix. Maybe for the fall, but for now I want sun blockage/evaporation reduction material that can float. Anybody have a source for reasonably priced sheets of such a material? An oblique bubble sheet, or something?
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
18,072
Northern NJ
It is the temperature differential between the warm pool water and cooler night air that causes the evaporation. You want to cool your pool water to reduce the evaporation. A pool cooler during the day and then a pool cover on the water only at night would be a bit of daily work but probably help.

You may find some ideas in...


 

BuckeyeChris

Well-known member
Jan 28, 2014
820
Buckeye AZ
I meant opaque. I’ll need obliques to lift them out of the water.
Yes I’m not sure I am committed or capable of taking them on and off every night and every morning. More likely when there’s a three or four day stretch coming up where nobody’s going to be swimming I will throw them on.
 

proavia

LifeTime Supporter
TFP Guide
Feb 6, 2015
1,872
Chandler AZ
Pretty much anything cover wise that you place on the water surface will retain heat in the water at night - and may slightly increase water temp during the day. But it will stop/slow evaporation.

A properly functioning water softener tied into your pools fill line will not add additional salt to the pool.
 

BuckeyeChris

Well-known member
Jan 28, 2014
820
Buckeye AZ
Pretty much anything cover wise that you place on the water surface will retain heat in the water at night - and may slightly increase water temp during the day. But it will stop/slow evaporation.

A properly functioning water softener tied into your pools fill line will not add additional salt to the pool.
Well, not salt but sodium, right? Years ago I did a side by side strip test of the pre and post softened water and the strips showed a much higher "salt" level.

Or else it's from years of using liquid chlorine...
 

proavia

LifeTime Supporter
TFP Guide
Feb 6, 2015
1,872
Chandler AZ
From years of using liquid chlorine would be my guess. I was surprised at my salt level when i got a Taylor K-1766salt drop test this spring. I don't use softened water for my autofill -- yet. And strictly a liquid chlorine diet for the last 3.5 years.
 

BuckeyeChris

Well-known member
Jan 28, 2014
820
Buckeye AZ
Well the point of using liquid chlorine was to not need to drain the pool due to high CYA, but if the salt piles up then I guess it doesn’t matter either way. What was your reading?
 

proavia

LifeTime Supporter
TFP Guide
Feb 6, 2015
1,872
Chandler AZ
Using tabs can push you CYA north of quickly. Some have reported exceeding CYA of 100 over the course of a summer. That will require at least a partial drain to keep it in check.

Here in the desert southwest, a big concern is hard water. Mine averages 225-250 out of the tap. And my entire pool volume evaporates at least one time per year. And since the CH does not evaporate, that means my CH increases about 250 ppm every year. That means I need to drain/refill every 3-4 years. In that same period of time, the salt level might reach 2500-3000 or so.