An Easy Introduction to Spa Chemicals

Maintaining your spa water is important, for several reasons: it prevents harmful bacteria from growing in the water, it protects your spa components from damage, and it makes for a more pleasant spa experience (i.e. no burning nose, stinging eyes or dry skin).

Weaving your way through the myriad of spa chemicals on the market today can be downright confusing. You can first refer to your owner’s manual. The manufacturer will make recommendations based on your particular spa. You can also ask for recommendations from your spa dealer. Don’t take this as gospel, however, as most spa dealers work on commission!

The following list explains the purpose of some basic chemicals for your hot tub:

Granular chlorine – Granular chlorine is often recommended for oxidizing your spa water, as it is a fast-acting, short-lived chemical. It can also be used as its own shock, and produces very little odor when used correctly. The strong chlorine smell that most people associate with chlorine is caused not by the chlorine, but a build-up of chloramines in the water. Chloramines can be easily removed with regular shock treatments.

Chlorine tablets – Although more convenient than granular chlorine, it is often not recommended for spas because it has a much lower pH that granular chlorine, and can cause damage the spa’s equipment is used improperly.

Liquid chlorine – Liquid chlorine, unlike chlorine tablets, has a very high pH, which causes the formation of calcium scale. This could result in difficulty when maintain the spa’s pH.

Bromine – Bromine acts in a similar way to chlorine, although it may build up in the water. It can be easily reactivated, though, by shocking the water with potassium mono per-sulfate or potassium per-oxy monosulfate. Many people prefer bromine over chlorine because it is usually easier on the eyes, hair and skin. Some people, however, may have an allergy to bromine. It is important to test the water regularly when using bromine, as it can cause equipment damage or the growth of bacteria.

Scale and Mineral Control Chemicals –It is important to use scale and mineral control chemicals, as a hot tub with a high mineral content can result in damaged components, which usually won’t be covered in the spa’s warranty. Most scale and mineral control chemicals have two components: an acid and a polymer. The acid breaks up any calcium scale in the water, while the polymer coats the minerals in the water and prevents them from forming scale. These chemicals come in many strengths, so it is best to refer to your owner’s manual before purchasing.

Shock Treatments – Most shock treatments consist of either potassium mono-per sulfate or potassium per-oxy-mono-sulfate, both of which are chemically similar to one another. They are generally used to shock the water when using Bromine tablets.

Clarifying Agents/Clarifiers – Clarifying agents consist of a polymer which binds particles in the water together, thereby enabling the filter to better eliminate them. Overuse of these chemicals, however, can create a sticky, brown scum that’s difficult to clean.

 Using the right mixture of chemicals in the appropriate levels is important in maintaining the healtiness of your spa.  You can always ask a spa technician to provide you with a lesson, with you taking over the regular maintenance thereafter.