Pool Chemistry 101 if you Live in Arizona.

Updated Jun 1, 2021

In addition to the usual suspects… algae, leaves, pollen, dirt, and body fluids, pool chemistry in Arizona means that list almost doubles, it can add up to a great deal of trouble for your pool and your wallet, if you don’t stay on top of everything.

To help you maintain that perfect pool water, we’ve created a definitive guide on everything you need to know about owning and operating a pool in Arizona.

From that guide, we have created this quick and easy reference article for you to get right into the pool chemistry details if you live in Arizona.

Arizona Pool Chemistry 101

Maintaining pool chemistry in Arizona is about 90% of your pool maintenance battle plan! If you don’t have a Smart Chemistry system to automate everything, there are still a lot of things you can test for, but the perfect Arizona pool chemistry can also be narrowed down to four things

pH, Alkalinity, Sanitizer, and Calcium

Here are the details…

pH Range for Arizona Pools

pH Range should be between 7.4-7.8.

But what will usually happen, is that pH will rise over time in your pool, and the normal range will end up being closer to: 7.4 to 8.2. Especially, in Arizona. So, you will want to keep an eye on this once or twice a week to avoid letting things build up.

CYA Range for Arizona Pools

Chlorine burns off when exposed to UV rays, and the Arizona sunshine is in full-force almost year-round. So, you’re going to need a little buffer to help keep your chlorine from wasting away.

Cyanuric Acid (CYA) is meant to stabilize the chlorine, so it doesn’t burn off too fast. It changes the water chemistry just enough to allow the CYA to continue sanitizing, even when the Arizona sun is shining. Think of it like sunscreen for your chlorine.

We recommend having a CYA range between 20 – 50 ppm of CYA in your pool to help buffer your pH scale.

However, if you put too much CYA, it can actually reduce the chlorine’s ability to sanitize, so don’t overdose. And it does not burn off. If you overdose CYA, the only way to remove it would be to drain and refill the pool.

Alkalinity Range for Arizona Pool Maintenance?

Many people confuse total alkalinity and pH. It’s understandable, given how similar the words like “alkaline” and “alkalinity” sound.

Total alkalinity is essentially your water’s ability to avoid changing its pH.

To be precise…

Too much alkalinity raises your pool’s pH.

Alkalinity makes it harder to reduce your pool’s pH.

The more alkalinity, the more muriatic acid it will take to reduce your pool’s pH.

We recommend having an Alkalinity range between 80-120 ppm.

Sanitizer Range for Arizona Pool Maintenance

Most everyone knows this already, but sanitizer just refers to the amount of chlorine, bromine, etc. in your pool water. Appropriate levels will vary based on the type of sanitizer you use.

We recommend having a Sanitizer range between 1-3ppm for safe swimming.

Calcium Hardness Range for Arizona Pool Maintenance

Everyone in Arizona pretty much knows that Arizona has a hard water problem.

For reference, any water measured with over 3.5 grains of calcium and magnesium bicarbonates per gallon is deemed “hard water.”

We recommend having calcium hardness between 150-400 ppm

That being said, some cities have hard water that borders at the top of the recommended range right from the start, so be aware of your city water hardness levels to better prepare yourself on how to handle things.

To give you some reference points, we have measured hardness variations across multiple cities, and you can see below that they are all so very different:

City Grains/ Gallon Hardness (PPM)
Apache Junction 13.6 232
Avondale 22.2 379
Cave Creek 13.5 231.1
Chandler 16.5 282.5
El Mirage 7 119.8
Gilbert 11.5 197
Glendale 15.8 271
Goodyear 24 410.9
Litchfield Park 11.1 190
Mesa 15.5 265.4
Paradise Valley 16 273.9
Peoria 10 171.2
Phoenix 14.1 241.5
Queen Creek 11.5 196.9
Scottsdale 19.2 328
Surprise 3.9 66.1
Tempe 13.9 238
Tolleson 8.5 144.5
Tucson 13.3 228
Yuma 20.2 345

* Those are yearly averages.

Calcium will build up over time and start messing with your pool chemistry.

Calcium also reacts with hot weather, something we have plenty of in Arizona, and tends to create an ugly ring around your pool tiles called, “scale” if it builds up over time.

Luckily, calcium scale is not an immediate issue that you have to worry about. It is a long-term process which means every 2-3 years, you will need to drain and refill

Why do Arizona Pools form Calcium Scale?

Calcium Scale in Arizona tends to form in the hottest water first… and secondly, it will tend to form where the water has the least amount of circulation.  And guess what? Arizona is hot! Really hot!

So why Arizona in particular?

The most common reason you see calcium scale in Arizona pools is that just about every city in Arizona has hard water, which can range up to 400 ppm.

So, there is plenty of calcium and magnesium in the water to begin with, allowing for the potential to start forming scale if your chemistry gets out of whack.

image of calcium-scale-in-arizona

These are the triggers to forming scale:

  • Your pool’s water Alkalinity is too high
  • Your pool’s water pH is too high
  • Your pool’s water temperature gets too high.

People might tell you the only option is to drain the pool if your hardness reads over 400 ppm, but it’s not necessarily the case.

For example, the city of Goodyear water measures 410 ppm right out of the hose, so draining is obviously not going to be the answer, because you literally just filled the pool.

Calcium scale in Arizona can damage your Pool and Equipment.

If you don’t stay on top of your hard water, it can quickly get out of hand. Some common issues occur, such as:

  1. Waterline on Tiles
  2. Scale Forming inside your Saltwater Generators (Salt Cells)
  3. Scale Forming inside your Pool Heater
  4. Cloudy Water

Conclusion

Anyways, we hope this guide was useful. We have been maintaining pools in Arizona for some time now and found that the above recommendations should keep you on the right track.