Hot Tub Sanitizing Systems – Chlorine

Hot Tub Sanitizing Systems – Chlorine

Chlorine is a sanitizer used in many swimming pools and hot tubs. The biggest source of algae, haze, and odors is the lack of enough chlorine. One part per million of free available chlorine is sanitary. This means it is completely devoid of bacteria. The water may look hazy, green, blue, or brown, but it is completely safe to swim in. More than 1ppm of chlorine may be needed if you have a high level of cyanuric acid.
Strong smelling chlorine may be a byproduct of having chloramines. Chloramines are organic waste combining with chlorine. Getting rid of chloramines is simple, just shock the water.
There are two main types of chlorine: stabilized and destabilized.

Calcium Hypochlorite

This type of chlorine is granular, has a log shelf life, and is destabilized. Since this chlorine is destabilized, it decays quickly in sunlight. This can be prevented by adding cyanuric acid to that water. It is approximately 65% free available chlorine. This type of chlorine is fast dissolving and raises the calcium hardness of the water. DO NOT MIX WITH DICHLOR! It is possible for a combination of Calcium Hypochlorite and Dichlor to start a fire.

Lithium Hypochlorite

This type of chlorine is a totally soluble, free flowing chlorine powder. It has 35% free available chlorine. It has less smell, has no residue, and has a long shelf life. This type is also destabilized, so cyanuric acid is a possible additive to slow the deterioration by sunlight.


Dichlor is stabilized sodium hypochlorite. This type requires larger but less frequent doses of chemicals. It also does not need to be tested as frequently. Since hot tubs are so frequently covered, it is unlikely that you will need the benefit of stabilized chlorine.
Chlorine also comes in liquid form. It is green in color and can be messy to use. In a solid form, chlorine is white and can easily be used in conjunction with a mineral system, ionizer, or ozonator. Never mix different types or brands of chlorine together. They can potentially be hazardous to your health and safety. All types of chlorine only work the same way once they are dissolved in water.
Chlorine is a simple and effective solution to both sanitizing and shocking a hot tub.