How Do You Kill Bacteria in a Hot Tub?

Hot tub folliculitis, also called jacuzzi folliculitis or spa pool folliculitis
Hot tub folliculitis, also called jacuzzi folliculitis or spa pool folliculitis

The best way to kill bacteria in a hot tub is by using chlorine-based sanitization methods. Chlorine helps kill various germs, although it takes some time to act. When used properly, free chlorine can kill most germs within a few minutes. Free chlorine is the more active form of chlorine that kills germs. The Centers for Disease Control and Prevention (CDC) recommends a pH of 7.2-7.8 and a free chlorine concentration of at least 1 ppm (parts per million) in pools and at least 3 ppm in hot tubs or spas.

If using cyanuric acid (chlorine stabilizer) or chlorine products with cyanuric acid (such as the products commonly called dichlor or trichloro), the recommended pH is 7.2-7.8 and the free available chlorine concentration must be at least 2 ppm in pools. CDC recommends that cyanuric acid or chlorine products with cyanuric acid must not be used in hot tubs or spas. Contact local agencies to help with the proper disinfection of a hot tub or spa pool.

What is hot tub folliculitis?

Hot tub folliculitis, also called jacuzzi folliculitis or spa pool folliculitis, is a skin condition arising within hours to a few days after bathing with warm water in a jacuzzi, spa pool or warm water swimming pool. The infection is generally caused by a bacterium called staph or staphylococcus aureus. It may also be caused by other microbes, such as Pseudomonas or candida. Hot tub folliculitis can be rarely caused by another bacterium called Aeromonas, especially in people using a spa pool.

The bacterium, Pseudomonas aeruginosa, commonly infects the public hot tubs that are under-chlorinated. The condition is commonly called pseudomonas folliculitis. The bacterium can grow on bath toys or wet suits that have not been thoroughly washed and dried after previous use. Children are usually affected more than adults. Pseudomonas folliculitis is generally seen in people with low immunity, such as young children, undernourished people and those with HIV or diabetes mellitus. People with skin conditions, such as dermatitis, and those who have recently shaved, waxed or epilated are also more vulnerable to folliculitis.

What are the symptoms of hot tub folliculitis?

The symptoms of hot tub folliculitis generally appear within a few hours to a few days after the exposure. Some exposed people may not develop the infection.

It generally presents as small scattered itchy red bumps, which are mainly seen over the trunk. They mainly affect the body areas covered by the swimming costume. The rash may become filled with pus (pustules) and cause pain. There is a feeling of malaise or being unwell along with fever, which is usually mild. Other symptoms may include sore throat, headache, earache, nausea and vomiting. In people with compromised immunity, such as those on immunosuppressive medications or those with AIDS, the condition may progress to cause a more serious infection called ecthyma gangrenosum. Ecthyma gangrenosum is a rapidly progressing skin condition characterized by the formation of several blisters and pustules that may cause skin necrosis or gangrene formation.


What percentage of the human body is water? See Answer
Goodman R, Vitous T. Hot Tub Folliculitis. Dermatology Nursing. 2010;22(3):47-49.

Centers for Disease Control and Prevention. Disinfection & Testing.