What is pH and How Does It Affect a Pool or Spa

What is pH?

pH scale

pH is the measure of the acidity of the water. The lower the pH the more acidic it is and the higher the pH the more basic it is. Maintaining pH, or potential Hydrogen, is simple and easy when you understand just a few basics. pH ranges from 0-14 with 7 being neutral.

How does pH affect a pool or spa?

Your pool or spa’s pH should be between 7.2 and 7.6. Your eyes’ pH is between 7.3 and 7.4, so the closer you are to 7.4 the less burning sensation you will have in your eyes. If your pool or spa’s pH is below 7 then the water becomes more corrosive and will start to wear away your metal components. For example your pump and your heater.  It also removes the plasticizers (what is in the vinyl that gives it its elasticity) from the vinyl liner.  Concrete and gunite are not immune either.  Low pH will cause pitting and chipping in the surface.

If your pool or spa’s pH is too high then it will start to build up scale. Scale can begin to form on the warmest parts of the pool, so the heater is the first victim. Scale acts as an insulator on the heat exchanger. That can run up the cost of operating your pool because you have to use more natural gas or electricity. And finally the higher the pH is in your pool or spa the less effective your chlorine will be, and the less sanitized it will be.

PH is just part of the overall makeup of your swimming pool or spa water chemistry.  In order to be balanced there are several other factors involved.   These include (but are not limited to) Total Alkalinity, Total Hardness, sanitizer levels, etc.  We will cover these topics in future blog posts.  Thank you for reading.