The most popular, economical pool shock available. Dissolves instantly and completely. Sodium hypochlorite is applied in swimming pools for water disinfection and oxidation. It has the advantage that microorganisms cannot build up any resistance to it. Sodium hypochlorite is effective against Legionella bacteria and biofilm, in which Legionella bacteria can multiply.
Due to the presence of caustic soda in sodium hypo chlorite, the pH of the water is increased.
The concentration of sodium hypochlorite that is found in swimming pools is generally not harmful to people. Sodium hypochlorite sometimes causes red eyes and it gives off a typical chlorine odor. When there is a lot of ureum (a mixture of urine and sweat) present, hypochlorous acid and ureum react to form
chloramines. These chloramines irritate mucous membranes and cause the so-called "chlorine smell'. In most swimming pools, these problems are prevented by water purification and ventilation. Eye irritation disappears after a while.
How Does Chlorine Work to Sanitize?
When chlorine is added to water, another dissociation occurs. When we add Cl2 (chlorine) + H2O (water), we get a reaction which leaves us with HOCl (hypochlorous acid) + HCl (hydrochloric acid). How much of each is created is dependent on water temperature, and especially on water pH. Hypochlorous acid is the active, killing form of chlorine. This is what does the real sanitizing work in your pool water. The chlorine molecule or ion kills microorganisms by slashing through the cell walls and destroying the inner enzymes, structures and processes. When this occurs, the cell has been deactivated, or oxidized. The hypochlorous molecule continues until it combines with a nitrogen or ammonia compound, becoming a chloramine.
Liquid chlorine is created by bubbling the chlorine gas through a solution of caustic soda. The yellow liquid (stronger, but chemically identical to bleach) has 10 - 15% available chlorine, and has a very high pH, on the other end of the scale at 13. Liquid Chlorine is called Sodium Hypochlorite (NaOCl), and because it is already in solution, sodium-hypo produces hypochlorous acid instantly when it contacts water. The liquid can be poured directly into the pool but it is recommended to use a diaphragm pump or a peristaltic pump to inject it into the plumbing. The use of liquid chlorine is more dominant in larger commercial pools which have it delivered in bulk quantities. For most residential pools, the lower cost seems to be outweighed by its difficulty in use and the amount of acid required to counteract its pH of 13.
*Use care when handling as this chemical is corrosive to just about everything.
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