In order to keep pool water crystal clear, chemicals are added to kill bacteria and algae. Sodium Hypochlorite (also known as Chlorine or bleach) is the most common form of chlorine used in Swimming pools. It is in liquid form and normally comes in a white plastic container. Chlorine is an Oxidizing agent. An oxidizer pulls electrons from a bacteria’s cell wall, therefore damaging and killing the bacteria.

Household bleach is around 4% in strength and liquid chlorine used in pools is around 12%. Chlorine will lose its potency with time. The sun’s Ultra Violet (UV) light destroys chlorine in pool water, therefore Cyanuric acid (Conditioner) is added to protect the chlorine from UV light. Organic matter such as sweat, urine and feces render chlorine ineffective. When combined with organic matter, chlorine produces chloramine, which has an odor and irritates the eyes. Often chloramine is present in a public Jacuzzi.

There are other forms of chlorine, which come in a powder form, Calcium hypochlorite (Cal hypo), Trichloro-S-triazinetrione AKA Sodium Trichlor and Sodium dichloro-S- triazinetrione AKA Sodium dichlor.

Sodium Trichlor comes in 1 inch and 3 inch tablet form, which can be placed in floating dispensers or inline tablet feeders, which are mounted on the pool plumbing. Sodium Trichlor has a low PH, which means it is acidic. Do not place chlorine tables in the Skimmer, because it can damage pool heaters, and plumbing, if your pool is plumbed in copper pipes.

Muratic or Hydrochloric acid is added to the pool to lower pH of the water, because Sodium Hypochlorite has a high pH, which means it is basic. Chlorine is more effective when pH of the water is 7.4-7.6

Pool water with a pH lower than 7 becomes acidic and can damage copper pipes and heaters.