How to test your pool water
To test the pH of swimming pool water, we suggest sticking with the classic drop-style water testing kit. It’s quick—takes less than 15 seconds—and it’s one of the easiest ways for pool owners to stay on top of water balance without running to the pool store all the time. Don’t be fooled, these test kits are surprisingly accurate!
Many of our customers have thanked us for this simple tip. These kits use the same type of reagents found in the high-end testing equipment used by pool professionals, so when used correctly, they deliver very accurate results. Keeping your pH in check is one of the best ways to keep your water looking crystal clear—and as a bonus, it could save you a lot on unnecessary chemical purchases.
Remember, testing your water regularly keeps your pool water clear and makes it fun to swim in. Also, many stain and surface issues are caused by bad water chemistry. We often say that if everyone maintained their water perfectly, we’d be out of business!
Ph - It's bigger than you think!
The pH scale measures how acidic or basic (alkaline) a liquid is. It runs from 0 to 14.
7 being neutral (like pure water),
Below 7 being acidic (like lemon juice),
Above 7 being basic or alkaline (like baking soda).
But here’s the trick: the pH scale is logarithmic, which means each step is 10 times more powerful than the last.
A pH of 6 is 10 times more acidic than pH 7.
A pH of 5 is 100 times more acidic than pH 7.
A pH of 8 is 10 times more alkaline than pH 7.
That’s why even small changes in pH can have a big effect on your pool water and equipment. Keeping your pH in the right range (typically around 7.2–7.6) is key to a healthy, balanced pool.
Why do they suggest a pH of 7.4?
A pH of 7.4 is recommended for pools because it balances comfort, safety, and equipment longevity. At 7.4, the water is slightly alkaline, aligning closely with the natural pH of human skin and eyes (around 7.2–7.4), which minimizes irritation. It also ensures effective chlorine disinfection, as chlorine works best in the 7.2–7.8 range.
Too low a pH (acidic) can corrode pool equipment and irritate swimmers, while too high (basic) reduces chlorine’s effectiveness and can cause scaling.
Chlorine is most effective within a pH range of 7.2 to 7.6. When pH levels rise above this range, chlorine’s ability to disinfect diminishes, leading to increased bacterial growth and the need for higher chlorine dosages.
pH and Pool Staining
Poor pH balance is the root cause of most stains that we see and can even make water unsafe for swimming. Our photo gallery shows severe cases where pH levels have strayed far from the correct range. High pH can lead to staining as minerals like metals, copper, calcium, or manganese bind to the pool’s surfaces, creating stubborn stains that resist brushing. Fortunately, our stain treatments can completely remove stains.
We often tell our customers that if everyone maintained the pH of swimming pool water correctly, it would reignite their love for their pool while saving money at the pool store.
If your pH is constantly high, try bringing a pH-balanced water sample to your pool store, as this can lead to big savings on chemicals. Just add some muriatic acid to your pool before taking a water sample. With the foundation of your water chemistry in check, you’ll often find you need fewer costly products! You’ll also get more accurate test results.
Final Thoughts
Pool water with low pH dissolves minerals, while high pH causes them to deposit onto the pool surface. The key to preventing this is maintaining proper pH balance. When the pH is balanced, it neither erodes nor adds to the pool surface, preserving its condition and extending its lifespan for years.
Balanced pH will extend the life and effectiveness of your expensive pool equipment and help keep your water crystal clear. Above all, the right pH makes the water safe and pleasant for swimming.
References
- pH scale – https://acidsandbases97.weebly.com/ph-scale.html
- Photo Gallery – https://poolstainremovers.com/pool-stain-removal-before-and-after/
- Test kit – https://www.taylortechnologies.com/
