The Association of Pool and Spa Professionals recommends free chlorine levels for both swimming pools and hot tubs be kept between 2.0 and 4.0 ppm. However, the Center for Disease Control recommends free chlorine stay above 1 ppm in pools and 3 ppm in hot tubs.
You should test your pool pH level as often as you test free chlorine – about twice per week. To raise pH use borax or soda ash (aka washing soda). To lower pH use muriatic acid.
Swimming Pool alkalinity (often called total alkalinity) is a measurement of the concentration of alkaline materials in your pool. Alkaline materials stabilize pH but buffer chlorine sanitation.
Total alkalinity is important to test and maintain. However, total alkalinity is largely similar and even correlated to cyanuric acid. Therefore, it is not as volatile as free chlorine or pH levels and does not require as frequent testing. A reliable rule of thumb is to test total alkalinity every other time you test pH levels.
Regardless of where you live or what kind of pool you own, you’re going to have to test your pool water chemistry. Testing your pool helps keep the water safe from viruses, bacteria, and algae and ensures chemical levels are safe and comfortable for swimmers.