The Foundation: Total Alkalinity
The chemistry of a swimming pool can be compared to a house. Every house must have a foundation. In the case of your pool, the total alkalinity is the foundation, because if it is incorrect, the rest of the pool water chemistry will eventually become out of balance. You must start with a solid foundation when building a house and you must begin the same way when balancing your swimming pool chemistry. The proper total alkalinity for your pool is 100 ppm.
First Floor: pH
The first floor of your pool house is the pH. pH measures the acidity of your pool water. The proper pH for your swimming pool is 7.4, for two main reasons. First, the pH of your eyes is approximately 7.4; your eyes will burn if the pH of your pool water is above or below 7.4. The second reason for maintaining a pH of 7.4 is that the water has a nearly neutral pH, which not only helps protect the finish of the pool and pool equipment but allows chlorine to work at its most effective level. There are several reasons why Total Alkalinity and pH relate to each other. If your Total Alkalinity is low (the fulcrum in the diagram below is pushed to the left), your pH will be low. If your Total Alkalinity is high (the fulcrum is pushed to the right), your pH will be high. Always keep your Total Alkalinity in balance (100 ppm) in order to maintain a proper pH level in your pool water.
Second Floor: Chlorine
The second floor of your “pool house” is chlorine. Chlorine is the primary means of providing daily sanitation for your pool. Chlorine will keep your pool water healthy and free from bacteria and algae. Chlorine is the second floor of the house because pH drives the effectiveness of chlorine. Just as you cannot have a second floor in a house without a properly-constructed first floor, you cannot have effective chlorine sanitizing without a proper pH level. If the pH of your pool water is too low, chlorine will be consumed too quickly and it will be difficult to achieve a proper chlorine residual (the amount of chlorine needed to provide daily sanitation). If the pH is too high, the chlorine in your pool will not work; though still present, it won’t be effective against bacteria, organic contaminants, or algae. The proper range for your chlorine residual is 1.5 – 3.0 ppm; try to consistently retain at least a 2.0 ppm chlorine level.
The roof of your pool house is your stabilizer level. Stabilizer is a chemical that helps protect pool chlorine from the destructive rays of the sun. Without stabilizer, chlorine will be used too rapidly, and you’ll have a difficult time maintaining the appropriate chlorine residual. Adding chlorine to your pool without stabilizer would be like air conditioning or heating a real house with no roof! The proper stabilizer level for your swimming pool is approximately 50 ppm.
Walls: Calcium Hardness
The final portion of your pool house is calcium hardness, which is pictured above as the walls of the house. Calcium hardness is important because it acts as a buffering agent to pool water by protecting it from the water’s corrosive qualities. Without a proper calcium hardness level, the finish of your swimming pool and your pool equipment will be subject to corrosion. A high calcium level is not a good thing either because it will cause scale to form. Scale is unsightly and can reduce the operating efficiency of your pool equipment. The proper calcium hardness level is approximately 300-350 ppm.