What Is pH What Should The pH Level Be For My Hot Tub?

Understanding pH and how to control it is crucial for every hot tub owner to understand in order to protect their investment and have the best soaking and ownership experience possible.

The importance of pH – the spa should be kept in a range of 7.2-7.8 to stay clear and comfortable. An optimal pH helps protect the efficiency of spa equipment, like heaters, and extend the life of the unit. Through the normal operations of a hot tub, both heat and aeration drive out carbon dioxide which causes pH to rise.

Low pH = Corrosive

  • Eye irritation and dry itchy skin
  • Low pH will lead to deterioration and corrode the spa interior and components                   

High pH = Scale Forming

  • Cloudy water
  • Hard deposit build-up on interior shell 

Both high or low pH will cause chemical inefficiency

Chlorine & bromine sanitizers become less active at high pH and alkalinity. Both sanitizers  become more active at a low pH. For purposes of hot tub water, water with a pH reading between 0-7 is considered acidic while water with a pH reading between 8-14 is considered basic.

What causes the pH in a hot tub to change?

Just about anything can cause the pH to change. The nature of the spa environment subjects the water to many conditions from numerous inputs.  Bathers – whose skin has a pH of around 6.4 – will cause the pH to decrease.  The chemicals we use to sanitize the water could have either a low pH or a high pH, depending on the product. The water that is used to fill the spa could have just about any pH depending on whether the water is from a municipal, well, or other water source. The aeration of the spa water will also tend to increase the pH.


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