Question: how deep should the pool be to keep best temperatures during hot summer

We are building a pool, and trying to figure out how deep and long the deep end should be in comparision to the remainder of our pool. We are looking at a 38 ft x 18 ft. pool and are being told to have a deep end in order to have comfortable water temps in July and August. Otherwise the water will be too warm to swim. We live in Columbia, SC and the location of the pool will receive 8 am until 7 pm full sun. Welcome any suggestions and past experiences. The shape we are considering is rectangle.

Hello, and welcome to the forum!!

I have an 18 x 36 rectangle, hopper-style pool with 8 1/2 foot deep end, and the water STILL gets very warm for swimming in July and August, unless I run tap water through my slide to cool it, or run my pump at night with a fountain. I'll let one of the engineering-types chime in here, but my personal opinion is that, if the pool is in full sun all day like yours, (and mine!), you're not going to be able to get a deep end deep enough to keep the water cool during the hottest part of the summer.
You might need to just explore other methods of cooling the water.

Thanks so much for your input. Makes sense and this is what our pool company is telling us too. Sounds like the hose may be the way to go. Courious as to the type of fountains you have. Do you find them beneficial. Getting conflicting advice on those to. Most are telling us that they are more decorative vs functional. Again. Thanks for your input.

The fountain I have plugs into the same return that my Polaris does. It has a center spout and 4 bubble-looking floats in a wagon-wheel sort of design. I think DH picked it up at Leslie's for around $100.

Most fountains are decorative, but this one serves two purposes--it does do some water cooling during the hottest part of the summer, and if you need to drop your alk or raise your pH, aeration is the way to do it, and it makes a fabulous aerator! :)

Okay. Thanks for sharing.

In South Carolina, you're not often going to have a pool be cool in August. There are several things you can do:

1. Make sure the surface is BRIGHT white. Any colorant in the finish will add several degrees. A dark color can add 7 - 10 degrees.
2. A spray type fountain used at night. SC is humid at night, so you're not going get lots of evaporative cooling -- you'd need a fairly high volume, going more than 2 or 3' in the air, to be effective.
3. Solar HEATING panels, with controls that allow them to be enabled at NIGHT, between 3 & 7am.
4. A deeper pool.