Clear Not Cloudy: Hot Tub Shock Treatment Tips

Hot tubs are great for relaxing your muscles, opening up pores, and for enjoying time with friends. That said, they can also become breeding grounds for scores of bacteria if they are not properly maintained. This article looks at the purpose of "shocking" hot tub water and explains how to keep your hot tub sanitary.

What is Shock Treatment?

Shocking refers to the application of either abundant chlorine or a non-chlorine shock agent to the water in your hot tub (or pool). Sodium dichlor is a chlorine-based shock treatment, while potassium monopersulfate (MPS) is a non-chlorine alternative. Both are designed to sanitize and enhance hot tub water.

Why Shock a Hot Tub?

There are a few reasons to periodically shock and hot tub. The first reason to do so is to break down organic wastes. These wastes can cause water to become cloudy or impart an unpleasant odor. Organic waste may come from your own body, but can also result from microorganisms (e.g. algae), which have made a home in the warm, nutrient-rich water of your hot tub.

Another reason to shock hot tub water is to convert chloramines back to chlorine. Chloramines tend to smell unpleasant (like medicine), though they do act to sanitize water. Chloramine levels are limited to 4 parts per million in drinking water, so it is also a good idea to keep hot tub water at a low concentration to avoid problems with accidental ingestion.

The final reason to shock a hot tub is to activate bromine that is being used as a sanitizer. Shocking converts the bromide ion to hypobromous acid, which kills bacteria, fungi, and algae. Without periodic shocking, bromine-based sanitizers will cease to function adequately.

How to Shock

How often you need to shock you tub depends on its size, ambient air temperatures, water temperature in the tub, and weather patterns in your area. In general, higher ambient temperatures, more frequent rain, and smaller hot tubs should all prompt more frequent shocking (every week), whereas shocking can be done every two weeks in cooler, drier climates. The best way to tell if a spa needs to be shocked is to monitor it for odors. If it smells, then you are past due for shock treatment.

Once you have decided when to shock, you will need to choose between the systems available. There are at least three different ways to shock a hot tub, each with advantages and disadvantages. The items needed to shock a hot tub should be sold anywhere that spa supplies are sold. Here are your options.

Ozone

Ozone is often used in combination with potassium monopersulfate. The benefits of this system are that you basically just dump the ingredients in and wait for a few minutes. You usually use these chemicals each time you use the hot tub, thereby avoiding complicated schedules, because ozone dissipates quickly and thus has no adverse health effects. The only real drawback of this system is that you do have to do it every time you want to use the hot tub (and once per week if you don't use the tub frequently).

Chlorine

Chlorine is the old stand-by. It very easy to use and compatible with any type of hot tub. The drawback to chlorine is that you cannot use the spa for one hour after application and it tends to have an unappealing odor. Chlorine needs to be used once per week in most cases, though may need to be used more often during heavy spa usage or when temperatures are high.

Bromine

Bromine is nice because it reduces the frequency with which shock treatments need to be performed and is compatible with just about any kind of hot tub. Bromine has less odor than chlorine. On the down side, you must wait much longer after applying bromine before you can use your spa.

Biguanide

Biguanide is used in combination with chlorine and thus is compatible with most hot tubs. Biguanide is appealing because it reduces the odors associated with chlorine. That said, it tends to be expensive and, because two products are used rather than one, tends to be more complicated.

Take Your Pick

That's really it. Just pick the treatment that you want to use and that works with your particular hot tub and then do it. Follow a routine to ensure that your tub stays in top shape and you shouldn't experience any problems. A spa supply store should be able to provide you with any additional details that you need.

Jeremy enjoys hot tubs. He often blogs about how to choose and maintain hot tubs properly.