When a car or a room is rented the occupant expects that everything will be well – clean, orderly and proper. If one were to use a hot tub, spa, or pool one should expect the same thing – clean, orderly and proper. Surprisingly, or unfortunately, this is not always true.

In 2004 the CDC published a disturbing summary of spa, hot tub and whirlpool violations from 5 states. About 11% (500/4,533) of these spa inspections resulted in the immediate closing of spas until the violation was corrected. Even today hot tubs, spas and pools are often unsafe and unacceptable for human occupancy. See why this is so.

Infected Hot Tubs, Spas and Pools – Microbe Soups

The club member came to the hot tub to relax at the end of a long work day. However, prior to getting in she noticed that it was cloudy and it had a slight odor that was a bit unpleasant. Fortunately, she decided to avoid using the tub and simply showered and returned home. This tub was heavily contaminated with several types of potentially-dangerous bacteria. The hot tub also had an inadequate level of bromine disinfectant (sanitizer).

How do microbes such as bacteria get in hot tubs, spas and pools? The answer is simple – microbes are shed from the skin and mucous membranes of the bathers into all of these waters. Another bather asks, “Are the microbes dangerous or harmful?” The answer is – the microbes may or may not be harmful. If they are dead then they are not harmful for an infectious disease.

If the microbes are alive they may be harmful should they be of certain dangerous types such as: Pseudomonas aeruginosa, Staphylococcus aureus, or even the common species Escherichia coli, or the yeast CandidaPseudomonas aeruginosa is a well-known culprit of folliculitis as documented in a hot tub epidemic of softball players in Alaska in 1986.

Spa, Hot Tub and Pool Infections and Diseases

Some bathers actually acquire skin and intestinal diseases from recreational waters such as pools, spas, or hot tubs.

  • Bacterial skin diseases may be simple rashes, or more dangerous ulcers, boils and abscesses.
  • Urinary tract (urethritis, cystitis) and genital (vaginosis) infections may result from the use of hot tubs and spas.
  • Often the responsible agent is a bacterium such as Pseudomonas aeruginosa, Staphylococcus aureus or Streptococcus pyogenes
  • Candida species of yeasts may cause infections and be spread in hot tubs and spas. Intestinal diseases include selected types of bacterial and viral infections acquired when contaminated water in the mouth is swallowed.

Since bacteria are common contaminants of the water and derived from the skin and mucocutaneous membranes of bathers there is a need is to continuously remove and destroy these bacteria to prevent infectious diseases.

Importance of Spa Filters and Sanitizers

Continuous removal and destruction of microbes in water can be done. Adequate bromine or chlorine at 2 to 8 ppm (parts per million) and a proper pH of 7.2 to 7.8 is usually sufficient to kill or inactivate many of the bacteria and viruses common in hot tubs, spas and pools. Further, efficient pumps and filters assure good circulation and contact of the bromine or chlorine with bacteria and viruses. Filters also trap and remove bacteria which are then killed or inactivated as the bromine or chlorine reacts with the trapped microbes.

Signs of a Healthy Hot Tub, Spa or Pool

Healthy recreational waters look, feel and smell good. Such recreational waters are produced by efficient filters and adequate levels of chlorine and bromine used at an optimal pH range of 7.2 to 7.8. All bathers need assurance that their bathing waters are tested, treated, maintained, and recorded in a daily log by qualified personnel. Knowing the basic facts of the bacteriology of hot tubs, spas and pools is a good first step for users and operators alike.

Bacteriology Facts

Every hot tub or spa comes with instructions and directions which should be read and studied by all owners and maintainers of the hot tub. After this is done then the maintenance and the microbiology is the most important instruction.

All people who use hot tubs and spas harbor microbes on their skin, mucous membranes and throughout the digestive tract. Here are some important, basic facts to remember about people, microbes and hot tubs:

  • some skin, mucus and tears are shed from everyone’s body throughout the day
  • many of these microbes are bacteria
  • some of the bacteria are able to cause skin and eye infections
  • bacteria include staphylococci, streptococci, enterics, pseudomonads, and others
  • these bacteria shed from the body can survive in water for varying periods of time
  • multiple people in a hot tub or spa shed their particular types and kinds of bacteria
  • some bathers will harbor more potentially-dangerous kinds of bacteria than others
  • bacteria in water may attach to a person’s body and grow on the skin or mucous membranes, or within the digestive tract if swallowed, and cause disease
  • persons with obvious skin infections, bandages, diarrhea, intestinal upset, or diapered babies should not use the hot tub since they are more likely to be highly infectious

Bacteriology, pH, Bromine-Chlorine Facts

Hot tub and spa manufacturers usually supply water test kits. Every spa owner should have a water test kit with all the appropriate test strips or tablets. This kit enables the owner to determine pH and concentration of bromine or chlorine — the critical factors needed to maintain healthy water for the spa or hot tub. Most spas and hot tubs use bromine as the recommended disinfectant. Here are facts and rules for maintaining a healthy spa or hot tub and for the safe control of microbes:

  • tablets of bromine are typically used
  • the tablets are held in a float or container with water ports that can be regulated by opening and closing. These ports permit more or less water to enter and exit the float
  • bromine and chlorine are both oxidizing agents that kill or inactivate microbes and maintain good health and sanitized water
  • pH must be appropriately maintained between 7.2 to 7.8 to optimize activity of bromine or chlorine
  • water tests and checks should be done daily or every other day at a minimum
  • tablets must be replenished on a regular basis depending upon bather load and use
  • the filter and pump should be run often enough to clear the water and circulate the bromine

Healthy and Unhealthy Hot Tubs and Spas Basic Ideas

Included here are the signs of a healthy spa or hot tub and a summary of the recommended pH and bromine or chlorine levels by CDC (“Healthy Swimming all year Long,” Cdc.gov) for routine care:

  • pH 7.2 to 7.8
  • bromine or chlorine level always at 2.0 to 4.0 or 5 ppm (parts per million)
  • water clear and free of any obvious debris (hairs or particles)
  • no burning of eyes or irritation of skin during or after use
  • pleasant odor to the hot tub

Of course any of the opposites of the listing above is undesirable. Most people would never enter a cloudy hot tub with or without unpleasant odors.

Maintaining a healthy hot tub or spa helps all those who use that hot tub or spa to have a refreshing time and to promote the health of the skin and the body.

Bathing should be the pause that refreshes without fear of infection– nothing more or nothing less could be asked by anyone.