Effects of pH (potential hydrogen) in hot tub water.
PH level in a hot tub is more important than you might think. I’ve come across many customers over the years that don’t ever test their PH level. They feel that if the water is clear, that’s all that matters. They add chlorine or bromine weekly (to kill bacteria) and as long as the water looks good they think all is well with their water.
PH is measured in a range from 0-14. This is the same PH scale you learned in science class in school. 0 is the low end of the scale and in water is extremely corrosive – acidic. With 14 being the high end of the scale and considered alkaline. 7 is neutral. The safest range to keep your hot tub water in would be 7.4 to 7.8. If the water in your tub is acidic it will corrode or etch any metal it comes in contact with. The heater in a hot tub is made of metal and won’t take long to corrode and then stop working in acidic water. Sitting in acidic water cannot be good for your body either nor will it feel comfortable. That being said, I have tested many hot tubs that are in an acidic state and the clients are so use to how it feels they aren’t even aware that it can and should feel so much better.
If the water in your hot tub is above the recommended range, it may also cause several problems. In most cases it’s scale and/or cloudy water. Scale in hot tubs is caused by high PH which allows minerals in the water to fall out of suspension and unto the tubs surface. This will leave behind a chalky or gritty residue on the tubs surface and inside the plumbing lines which can break down plastic or rubber components in the hot tub and your water can become cloudy. When the minerals in the water fall out of suspension they “show themselves” in the water.
Several factors can cause PH to change in the water. The two most popular reasons are source water when topping up as well as the sanitizer. If you fill with hard water or well water, your PH will raise dramatically. Most well water comes out of the ground at a higher pH level. When doing a fresh fill from a well or city water immediate testing by a water care specialist allows you to analyze the source water. The sanitizer used in the tub will also affect the pH level. If you are using dichlor (stabilized granular chlorine) it has a PH factor of 6-7. however if you use Calcium hypochlorite (unstabilized granular chlorine) it has a pH factor of 12-13. Bromine is the preferred sanitizer and has a pH factor of 4-5.
Just because a hot tub looks clean and has clear water don’t assume everything in the water is fine. A hot tub with water in it that measures at a 6.0 pH level will be crystal clear. The reason being, nothing can grow in acid. The heater and other hot tub equipment will begin to corrode away and your eyes and skin will burn, but that water will look great. Do yourself a favor and test your spa water weekly for sanitizer and pH. Overall it will save you time, money, and possibly your health. You can use the test strips however remember they are a guide. Proper water testing by a professional is always recommended every 6-8 weeks. Find a company you can trust and who cares about your water quality. At Knapp’s Pools and Hot Tubs we will only sell you what you need and there is never any pressure to buy. We also offer on site water testing which allows us to ‘see’ the water we are testing and walk you thorough proper water maintenance.
Happy Hot Tubbing!