pH is one of the most important factors in pool water balance. It should be tested and corrected at least once every week. pH is the measure of how acid/ alkaline the swimming pool water is. The pH of the human body is 7.2. This may conclude why this number is also perfect for the pool. When pH drops below 7.0 the water becomes acidic. Anything above 7.0 is alkaline. There are many problems that can occur from having low/high ph.
Low pH can cause your liner to dissolve, corrosion of all the metals associated with your pool (ladders,rails, pumps, filters, valves, ect), staining from the metal corrosion, rapid dissipation of chlorine resulting in having to use more & more, and dry & itchy skin. High pH can cause scaling or calcium buildup on pool surfaces, waterline and accessories,dull or cloudy water,clogging of filter medium or elements,dry itchy skin, and drop in disinfection potential of chlorine resulting in algae growth.
Keeping your pH adjusted properly is not a hard job, it just takes weekly testing and maintenance. It can be tested with strips or a traditional drop kit. If you find that your ph is to high, you will want to add acid to bring it down. A good rule to go by is 1/4 gallon of muriatic acid for every .1 ppm you need to lower per every 20,000 gallons of pool water. For example, if your pool is 20,000 gallons and your ph is 7.8 & we want to lower it to 7.4 thats .4ppm. We would use one full gallon of acid. If your pH is to low, you will want to use soda ash. Soda ash is commonly called, pH up. The formula for soda ash is a 1/2 lb for every .1 ppm you want to raise per 20,000 gallons.
Learning the formulas & names is the most difficult part of the pool chemistry. Once you have completed the task a few times, it becomes second nature. If you will develop the good habit of testing & adjusting your chemistry at least once a week you shouldn't have any problems.