Unstabilized Chlorine Sanitizers - Pool Chemicals Inactivate Most Mcroorganisms

Unstabilized chlorine sanitizers are very effective at killing algae and pathogens that cause diseases in swimming pools. Still there are some parasites that are not easily controlled by all swimming pool chemicals. Some of these parasites include giardia and cryptosporidium.

Swimming pool chemicals that are considered unstable, do not contain any carbon atoms in them.

Since these pool chemicals do not have any carbon atoms, they are referred to as inorganic pool disinfectants.

Unstabilized chlorine sanitizers are very sensitive to the ultraviolet radiation found in natural sunlight.

This means that the strength of the chlorine residuals quickly lost during hot sunny days.

Good water quality depend heavily on these unstabilized chlorine sanitizers!

Swimming pool disinfectants that fall under the unstabilized category include....

Sodium hypochlorite. This chlorine based swimming pool sanitizer, is the most commonly used disinfectant in public or commercial pool care. The active strength of this pool chemical ranges from between 10% and 12% with a pH range of 13. Sodium hypochlorite will raise the total dissolved solids (TDS) and the pH of your pool or spa water. Total dissolved solids or TDS, are the total weight of all soluble matter in your pool water.

In other words, all dissolved solids that are added to your pool or spa, contributes to TDS. Although sodium hypochlorite is a contributor to your TDS levels, it will not have any negative effects on your swimming pool sanitation. Unstabilized chlorine chemicals like sodium hypochlorite are not very stable when in storage.

This means that they will loose their strength gradually. The lost in strength reduces the benefits of this chemical (sodium hypochlorite) economically. This happens especially at very high temperatures. And for this reason, manufacturers recommend that you store this pool chemical in a very safe and cool area.

Calcium Hypochlorite. This swimming pool chemical is a dry form of chlorine. It is often referred to as cal-hypo. As a pool or spa owner/operator, you have the option of purchasing this particular pool sanitizer in either granular, tablet, or briquette forms. The active strength for this member of unstabilized chlorine sanitizers, ranges from 65% - 78% with a pH that ranges from 8.5 to 11.

Calcium hypochlorite is a pool disinfectant that is mostly used for superchlorination. It is also good for use as the primary disinfectant in erosion feeders. Still you have to be very careful when using this unstabilized chlorine sanitizer because you can raise your chlorine levels significantly.

One pound of cal-hypo that has either 65 or 78 percent active strength, can shoot your ppm (parts per million) levels up to 7.8 0r 9.4 respectively. If you use this pool sanitizer continuously, the balance of your pool or spa water will be affected due to high calcium levels. For those of us that live in areas where our make up water is hard, high levels of calcium can result in the formation of scaling.

This scale build up can be seen in several places in your aquatic facilities. They include:

  • The wall surfaces of your pools.
  • The wall surfaces of your spas.
  • In your swimming pool filters.
  • In your heating and circulating components.

However if you live in an area where your make up water is soft, then cal-hypo will be of benefit to you.

It adds calcium hardness to the water. This is beneficial how you ask? Well it adds to the overall balance of your pool chemistry.

According to the National Fire Protection Association, this member of the unstabilized chlorine sanitizers, is classified as a class 3 oxidizer.

This means that it can accelerate severely and ignite, if it ever becomes contaminated or heated. Cal-hypo is incompatible with organic compounds, therefore you should take extreme caution when storing and handling this pool disinfectant.

Lithium hypochlorite (LiOCL). Again this is a dry, granular form of chlorine that is used in swimming pool sanitation. It is an excellent choice for superchlorination of your pools because it is completely soluble and it responds quickly. The active strength of this chlorine based chemical, is 29% and it has a pH range of 10.8

Lithium hypochlorite is not commonly used as a treatment in commercial swimming pool facilities. This is simply due to the fact that it has a very low active strength. Still because this pool and spa sanitizer dissolves very quickly, makes it ideal for disinfection in:

  • Pools that are lined with vinyl.
  • Pools that are made of fiber glass.
  • Pools that are painted.

Lithium hypochlorite can also be a good source of treatment in spa water care and in regions that have very hard water. Again this member of the unstabilized chlorine sanitizers, has been classified as a class 1 oxidizer. This means that combustion of this pool and spa chemical can be accelerated; thus, it can ignite if it is contaminated or heated.

Chlorine gas. The active strength of this pool disinfectant is 100% and it has a pH of zero. Chlorine gas is a great swimming pool sanitizer but it rapidly lowers the pH of your water. This process actively destroys the buffering capability of your pool water. It means that you can not use this sanitizer by itself. You have to use another pool or spa chemical to bring up or maintain the pH level of your water.

Pool chemicals used to raise the pH of a swimming pool!

Chemical that are commonly used to raise the pH in a pool or spa include:

  • Sodium carbonate otherwise known as soda ash.
  • Sodium hyproxide (NaOH), otherwise known as caustic soda.

Over the years, the number of swimming pool facilities that use chlorine gas as their means of disinfection, have diminished. This is irregardless of the low cost and effectiveness of this pool disinfectant. The real reasons for the reduced use of chlorine gas are:

  • The cost of maintaining and repairing the feeder equipment.
  • High insurance costs.
  • High toxicity level of the chlorine gas.

  • Effects of a leak on the facility.
  • High operator training requirements.
  • Effects of a leak on the staff and the surrounding community.

Because this chemical is a member of the unstabilized chlorine sanitizers, you will have to use a stabilizer like cyanuric acid to protect your chlorine residual.

This is a necessary procedure because in direct sunlight, chlorine based chemicals that are unstable will quickly dissipate.

In other words, without any form of stabilizer, your chlorine content can be completely destroyed in less than an hour. As a result of this, your free chlorine concentrations can fall well below the recommended level of 1.0ppm. As we all know, low levels of disinfectants in a pool or spa will raise the risks of waterborne diseases and swimming pool contamination.

Something to remember here! Cyanuric acid has no sanitation or disinfectant capabilities. Its only function, is to stabilize your free chlorine concentrations. It will not stabilize bromine. So as you can see, with a little precaution and a good stabilizer, you can effectively disinfect your pool with unstabilized chlorine sanitizers.

Unstabilized chlorine sanitizers are a part of your pool chemicals!

Swimming pool care home page.

Back To Top

New! Comments

Have your say about what you just read! Leave me a comment in the box below.