cooling the pool in Phoenix

[hikernut]

Hi,

I am buying a house in the Phoenix area that has a diving pool. This will be my first experience as a pool owner, so I expect I'll be checking in here from time to time when I have questions. Looks like a fantastic resource.

I'll start with a question about keeping the pool cool enough to be refreshing. Toward the end of summer in Phoenix, my experience (in other folks' pools) is that the water can get so warm that it no longer serves as a respite from the heat.

I've found a few ideas online. The one that appeals to me most is what I'll call a "sail shade". My understanding is that it should reduce the solar input to the pool. Of course, it will also provide shade for the pool's occupants.

Any comments from people who have done this? How much cooler is the water when shaded, as compared to full sun? Did you try to shade the entire pool, or just part?

Thanks,

hikernut

[Pool Palace Dave]

I don't know if this will help or not. I've had this problem in E. Washington at times. I usually have to run my filtered water through passive solar panels (black plastic tubes heated by the sun) to warm the pool to acceptable temps for the grandkids. If we get too much hot weather and the heating is not shut off, the pool gets too warm (got over 100F one time). What I did to cool the pool down was to run the water thru the solar panels at night after the air and ground temp was low enough to cool rather than warm the pool. I know that it stays pretty warm in Pheonix pretty late, but maybe running it from 10 pm until 8 am might help you as it has occasionallly helped me.

[Watermom]

Dave is right. Running solar panels at night is one of the things we frequently suggest here on the forum as a way to help cool a pool.

By the way, I want to welcome you both to the Pool Forum!

[BigTallGuy]

I live in Mesa and agree that my AG pool water can reach as high as 96° F in the summer. Anything you can do to shade the pool will help. The problem with shades, umbrellas etc. is keeping them out of the pool during storms, and just in general. I have not personally tried a sail shade but it doesn't sound like a bad idea as long as you secure it properly.

[hikernut]

Thanks for all your comments. I paid for a subscription today... hopefully that helps to keep the site kicking!

Re: Running water through solar panels at night. During the "problem" (i.e., hot!) time here it can be over 100 F at midnight, with overnight lows in the 90s. I'm a bit skeptical that I'd get much cooling during those nights; it would have to be from radiation loss. Anyone having success with this in the Phoenix area?

If I add a shade, it will be a proper setup. Not just a blue tarp with some rope.

Just trying to understand what I could expect in terms of delta-temp. If it's only a couple of degrees it wouldn't be worth the bother. Ten degrees... now we're talking.

Thanks again,

hikernut

[aylad]

Hi hikernut,

Just wanted to say thank you for your subscription and for helping support this site--we appreciate it!!

If you decide to set up the shade, I'll be interested in how it works for you. I'm in Louisiana with full sun on my pool all day, and we have the same "hot tub" effect that you get--toward late July/early August, it often gets too hot to swim!! So far we combat that by running the pump with a fountain at night, and running tap water through the slide during most swimming sessions, which substantially cools the water, but I'm lucky in that water from my tap is almost perfect chemically, so it doesn't affect my pool chemistry at all. If a shade of some sort would make a huge difference, then I might be interested, as well. If you go that route, make sure and let us know how it works!!

[hikernut]

aylad,

Thanks for sharing your experience. If I do put up a shade, I'll report on the effectiveness here.
I'm considering solar pool heating as well, so it might make sense to do that project first and see if it can provide some cooling during July/August in Phoenix.

To all... is there any software available to model pool temperature? I know it's a long shot, and if it exists it probably costs a lot anyway??

hikernut

[Phillbo]

I run my pump at night (cheaper rates) and during the hot season I turn on the aerator. Not sure how much it helps but I'm sure it helps some.

[hikernut]

I've been cruising the website for a few days, and getting educated. Great resource. I'm sure you folks hear that a lot!

One more thought on the shade... In addition to making the water more refreshing, am I right in thinking that it would make the summer pool maintenance easier...
(1) Because the water is cooler, and the nasties grow better in warmer water?
(2) Because the shade blocks at least some of the chlorine-damaging UV light (assume the shade blocks UV, for now anyway).

Assuming my thought process is correct here, any idea which of the two effects is the more important one?

Thanks,

hikernut

[aylad]

I Don't know about thought #2, but as far as #1 goes, I don't think you will see a appreciable difference in algae growth with a few degrees difference in water temp. Algae will grow just as well in 80 degree water as it will in 90 degree water.

[BigTallGuy]

Aylad is correct. You will not reduce the water temp any appreciable amount that would require a change in your water chemistry. You will still need to do the normal chemical basics.

[hikernut]

Hi,

Understood that there's no magic bullet here. Still need to test and adjust regularly.

I was reading the "Pool Tips" over on poolsolutions.com. Tip #6 says to add chlorine in the evening instead of the morning, since "During the day, it mostly is wasted -- lost to UV in the sunlight." Using this logic, I would think that some shade would help. Maybe I'm splitting hairs here?

Thanks,

hikernut