How To Keep Pesky Parasites Away From Your Hot Tub

hot tub

Hot tubs, spas and Jacuzzis are recreational equipment for hydrotherapy and relaxation.

As soon as water fills the basin, it becomes an aquatic microbiome.  Any chemical, mineral or organism stays in the water unless it is filtered out, chemically treated or removed.  A hot tub owner or operator may not know if all of the microorganisms are taken out of the water system.  But much of the aquatic diversity cannot be seen with the human eyes.

A common myth about microbes is that hot water must kill off anything that could be living inside the water column.

Although water boils at 212°F (100°C), typical hot tubs and Jacuzzis allow for water temperature between 95°F-104°F (35°C-40°C).  The personal comfort level can keep the water warmer or cooler with many of the settings.

Along with proper maintenance, the water is purified between uses.  Depending on the frequency of use, water depth and number of individuals using the hot tub; all determine how often the water is drained then refilled.  Water odor, clarity, and film/foam in the upper layer could all indicate potential issues with quality.

Water treatment and chemical shocks purify the water and destroy most microorganisms in the water, but some still can survive if the water is not hygienic and could actually thrive in hot water alone.

When humans enter the water or use the water; they come into contact with these organisms.  The majority of them are harmless and can easily be ignored by our immune system.

They do not cause illness or disease.  Their benign nature cause no health effects.  But there are some water-bound protozoan pathogens that cause health concerns all around the world, but especially in recreational hot tubs, spas and Jacuzzi tubs.


Protozoa are a unique group of microorganisms.  They are multi-cellular and live in many habitats including the aquatic environment.

Some can swim with the help of tails called flagella.  Others can grab onto hard surfaces with tiny hair-like projections called cilia.  Still others simply flow with water and cannot move or swim.

They can have extra external armor that protects them from drying out.  This outer membrane is one of the problems with traditional water treatment.  Chlorination and chemical treatment procedures cannot penetrate the shell and becomes ineffective against killing the protozoa in water.

The protozoan life cycle is quite varied.  They can replicate rapidly and offspring can remain suspended in a dormant cyst stage, for future emergence when the environmental conditions are better.  Other protozoan species only exist as parasites.

What is a Parasite?

A parasite requires a host to survive.  They need specific nutrients or blood meals from their hosts.  Since a host is considered to be temporary housing to the parasite, hosts are rarely destroyed or killed by the parasite.

Some parasitic infections cause humans to become very sick as their body is attempting to fight off the microbe.  Children, pregnant women, elderly and anybody with weakened immune systems have difficulty fighting these parasites.  They are at greater risk to water quality impairment.

Let’s take a closer look at some common parasites.


Cryptosporidium is a public parasite also known by the abbreviation Crypto.  If infected water enters the mouth or is swallowed, the individual can get sick quite rapidly.

Common symptoms include diarrhea, vomiting, stomach pain and nausea.  For most people, the infection will run its course and not need medications.  Dehydration is a minor risk.1.

Giardia intestinalis

Giardia is present in contaminated water and attaches to the small intestine in humans and animals.  As it feeds from the nutrients during digestion, the gastrointestinal system starts fighting off the infection.

Stomach aches, diarrhea and vomiting overcome the individual in the hopes of expelling the parasite from the body.  Individuals will need medical attention to combat this parasite.  Stool samples will be taken to correctly diagnose the infection.

The Centers for Disease Control and Prevention mentions several medicinal treatments that include: Metronidazole; Tinidazole; Nitazoxanide 1; Paromomycin; Quinacrine; Furazolidone. 2.

Keeping You and your Hot Tub Healthy

Water parasites can be prevented easily.

Water filtration is the first line of defense against these organisms.  Any stage in their life cycle will be captured in most filtration systems.  All hot tubs and spas have standard operating procedures for proper water filtration with primary and secondary treatment.

In addition to chlorine additives or shock treatment, Ultraviolet Light and/or Oxidizers are suggested.  This will eliminate any possible parasite threat to the water supply.

As a precautionary measure, if someone is believed to have been taken ill by a parasite, draining the facilities and thoroughly cleaning the basin and tanks will further prevent the spread of any parasites to additional hosts.

If a person has been ill between 2-7 days with vomiting, diarrhea or other symptoms from water parasites, kindly ask them to be courteous and not use the hot tub or spa.

With these simple steps, you can gain positive benefits from hydrotherapy and maintain perfect water conditions in your hot tub, spa and Jacuzzi.


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About the Author:

Natalie Abram
Natalie is new to freelancing, but has worked as an aquatic content editor for the past 7 years. She teaches biology online at multiple schools. Her background and Master’s education is in Biology, Aquatic Ecology and Education.

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