Pool Chlorine, Water Tests, and Saving Money

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It is well documented that there will be a pool chlorine shortage this summer. Make that, there IS a chlorine shortage, right now! A fire that destroyed a major chlorine production facility in Louisiana has reduced available chlorine nationally by over one-third.

Chlorine Tablet Shortage Due to Covid-19 & BioLab Fire

Therefore, it is essential for pool owners to lengthen chlorine life to make it stretch farther. The easiest and least expensive way to do this is by maintaining proper water chemistry. Here, we will examine four variables that affect chlorine life in invisible ways.


For this article, we shall define pH as the degree of acidity or basicity of your pool’s water. It is measured on a 0-14 scale, with anything below seven being acidic, and anything over seven being basic. Seven is rated as neutral, neither acidic nor basic. Hydrochloric acid scores a zero—as acidic as you get. On the opposite end are things such as liquid chlorine and ammonia, both nearing fourteen. Click here for a visual guide to the scale.

If your pool’s water is acidic, chlorine becomes hyperactive. Simply put, it burns out quicker and doesn’t last as long. So, you need more of it. Conversely, if the pH is too high, then it simply gets locked up and you run a greater risk of algae growth. To complicate issues, the scale is a little misleading as it is exponential, or logarithmic. In other words, when pool water drops from seven to six, it becomes ten times more acidic. A pH of five is one-hundred times more acidic than at seven, and at four, it is one-thousand times more acidic than neutral water. The same is true going the opposite direction into the basicity range. In short, a little out of balance can translate into a big headache.

Furthermore, a pH that is out of whack can damage pump seals and gaskets or cause scaling and cloudy water. It can also affect your skin, causing tingling or irritation. Keep your pH in the range of 7.2-7.8, as slightly basic water is preferable to completely neutral water. This will maximize chlorine life and helps protect you and your pool’s components. So, that’s all you need to do to effectively balance your pool’s water. Right? Unfortunately…no.

Total Alkalinity

A proper alkalinity level helps hold the pH in line. If your alkaline content is at or near zero, you can adjust your pH daily, but it won’t hold. It will bounce like a child on a trampoline. Think of alkalinity as a pH stabilizer. While there is some discussion on what the proper level is, Eastgate Pools recommends 80-150 parts per million (ppm).

To raise your alkalinity level, add Alkalinity Increaser. If it is too high, lower it by using pH-Minus. Note that Alkalinity Increaser will also raise your pH, so when balancing your water, always adjust the alkalinity first. You can then complete the final pH adjustment.

Some areas have water that comes out of the ground with extremely high pH and alkaline content. This may require a heavy dose of pH Decreaser, added GRADUALLY over several days. You may get a little frustrated, as both pH and alkalinity levels may be locked in. However, keep on dosing and eventually, both levels will begin to drop. Once they start, keep a close eye on the levels as they will now adjust more quickly.

Cyanuric Acid

If you go to the beach, you use suntan lotion to keep from getting a sunburn from strong UV rays. Swimming pool water needs Cyanuric Acid to protect chlorine from that same strong UV sunlight. The chemical formula is C3H3N3O3, but let’s just call it CyA. Simplified, sunlight burns chlorine out of the water. CyA helps minimize the effect and gives chlorine a longer life. For this reason, it is frequently referred to as chlorine stabilizer.

It is an acid, so keep an eye on your pH and alkalinity levels after adding it. However, it is a weak acid and will not have the same affect as adding a strong acid. Generally, Eastgate Pools recommends a minimum of 30 ppm in liner pools. Using stabilized chlorine tablets adds a little CyA to the water, restoring what is lost through backwashing or waste-water disposal. It also lets you slowly built the CyA level further over time. You may eventually need to drain some water to reduce the level if it has gotten too high. Think of it as giving your pool a drink of fresh water.

If you have an in-ground pool equipped with a chlorine generator, you will need to start with a higher CyA level. Chlorine generators work great, but the chlorine made is unstabilized and will burn out quickly without the addition of CyA. We recommend starting with a minimum of 70 ppm of CyA.

Maintaining a proper level of Cyanuric Acid adds life to your chlorine. It also stays in the water well from season to season, so don’t add it automatically in the spring. You may not need it.

Calcium Hardness

This is the final piece to the water-balance jigsaw puzzle. Concisely stated, soft water in a pool is bad, with a capital B. It is corrosive to pool components and makes adjusting the pH virtually impossible. A proper calcium level buffers the water and makes it more receptive to other balancing chemicals. The proper calcium level for your pool is dependent on the type of pool and the sanitizing system you use. Please contact your pool professional to determine the calcium level that is proper for your situation.

“I’m No Chemist.”

You don’t have to be. I can’t speak for the testing abilities of other pool retailers. Some will be more knowledgeable than others. However, I can vouch for the pros at Eastgate Pools & Spas. Everyone is trained and understands the delicate job of balancing pool water. Eastgate Pools uses the state-of-the-art Pooltest 25 Photometer from water-analysis pioneer Palintest. It provides highly accurate test results for all the above fields as well as many other specialized water components. If you have a staining problem, we’ll check for iron and copper. Ongoing algae issues? We’ll analyze your phosphate levels and work with you to get it under control. Do you need to know your salt level to keep your chlorine generator running properly? We can do that, too, and much more. Plus, it’s a free service, so take advantage of professional testing and expert analysis.

If you are a hands-on, do-it-yourselfer, Eastgate Pools offers quality home test kits. They are easy to use and provide a great way to monitor your pool water balance. Even so, I recommend bringing a water sample to Eastgate Pools several times each summer to verify your analysis.

In conclusion

Keeping your pool properly balanced will keep money in your pocket and you in the pool. We’re here to help, so always feel free to stop in or call if you have questions.

Next time, I’ll discuss specialty products that will help you stretch chlorine life while keeping your water crystal clear. Also, I’ll offer some tips on pool maintenance you can do to reduce chlorine waste. Until then…happy swimming!