Water is an essential part of life for humans and other living organisms. Thanks to its great ability to dissolve other substances, it can support the growth of microbes that affect human health. As we shower, we can become exposed to some pathogenic microorganisms if the water is not properly treated.
Shower filters that are capable of ultrafiltration can remove bacteria from water. Shower filters with KDF-55 media and/or nano silver can prevent the build-up of biofilms (structures comprising groups of bacteria) inside the shower filter but are not able to actively remove bacteria from your shower water.
In this article, we will learn all about the harmful microorganisms that often travel across our water lines, including viruses, cysts and bacteria. We will discuss whether any filter can prevent your shower head from spitting contaminated water, and offer recommendations on the best treatment for your tap water.
What kind of bacteria can you find in tap water?
Waterborne bacteria (and other germs) are regular appearances in plumbing components such as pipelines, water heaters and faucets.
It is virtually impossible to eradicate them from the tap water that pours out of your shower, even if your water is sourced from a local utility, regulated by federal and state laws, or if you are consistent with the maintenance of your private well.
As the water flow enters your property, it can pick up contaminants that line corroded or cracked pipelines, stagnant water storages or dirty shower heads.
There are three primary types of organic water contaminants: viruses, cysts and bacteria.
Viruses are small and simple infectious agents that cause a variety of diseases in humans, from common colds to typhoid fever. They are easily removed with chlorination, the most common disinfectant procedure applied in municipal water supplies.
Most filtration systems are not overly effective in removing viruses.
Water Purification Guide has detailed information on which water filters can remove viruses available here.
Cysts are infectious microorganisms that are larger than viruses and bacteria. For that reason, they are more resistant to chlorination. A person can become infected if they accidentally swallow contaminated water while having a shower.
But contamination is easier to identify through regular testing thanks to the size of these microbes, and several filtration systems are quite effective at removing a few of the main cyst species.
Thus, the cases of disease outbreaks due to cysts in local drinking water supplies are rare. Several filter pitchers are effective against cysts, including Clearly Filtered’s water filter pitcher, or the Epic Nano Pitcher.
Bacteria are naturally occurring groups of microscopic organisms consisting of one single cell. Most bacteria are harmless and even beneficial to the metabolic activities of humans. However, some bacteria are pathogenic, which means that they can cause diseases.
Chlorine is highly effective at killing bacteria.
Some of the most common bacteria that may grow in your water system, with potential harm to human health, include:
- Nontuberculous mycobacteria: environmental organisms that are found in natural and municipal water sources. They can cause respiratory infections, especially in people with underlying lung disease or depressed immune systems.
- Legionella spp.: bacteria that can cause a serious type of pneumonia. They are found naturally in freshwater environments but can grow and spread in showerheads and faucets.
- Pseudomonas aeruginosa: a common type of bacteria that can cause various infections like otitis, conjunctivitis, and folliculitis.
Is all bacteria in water harmful?
If your water supply is contaminated with any waterborne bacteria, there are a few ways in which they can permeate your body:
- Inhaled as a mist of aerosolized bacteria.
- Contaminated water comes in contact with damaged (e.g., a cut) or diseased skin.
- Contaminated water goes up the nose or is splashed into the eyes.
However, most healthy people exposed to the germs that are in tap water rarely get sick.
On the contrary, they’re believed to strengthen the person’s immunity response. But there are some people who are more susceptible to microbes than others. The main risk groups are:
- People over 50 years old.
- Current or past smokers.
- People with chronic lung disease.
- People with serious medical conditions and compromised immune systems.
- People with diabetes, kidney failure, liver failure or other underlying illnesses.
- Children under 6 months old.
Healthy people need not worry too much about showering with tap water. In fact, even in areas with boil water advisory, you can typically shower and even bathe, as long as you exercise extra caution not to swallow any water.
However, if you have any skin condition, it might take longer to heal as the damaged skin repeatedly comes in contact with infectious microbes.
Can I remove bacteria with my shower filter?
Shower filters can seldom remove waterborne bacteria, but you can find some units that reduce the chances of developing a biofilm (structure of different bacteria colonies) in your shower head.
The effectiveness of a shower filter in removing or reducing the bacteria present in your water depends on the filtration technology. The methods that are recommended by the CDC to fight harmful bacteria and cysts are:
- Ultrafiltration systems
- Nanofiltration systems
- Distillation system
- Ultraviolet (UV) or ozone purification systems
- Reverse osmosis systems
Reverse osmosis systems are usually installed at the point of entry, before your water supply reaches the shower head. The other technologies mentioned above are rarely found in commercial shower heads.
In fact, most home water filtration systems are equipped with carbon filters that are NOT the most efficient at removing bacteria for two reasons:
- Germs build up in biofilms that can grow and spread inside the carbon filter if not properly maintained.
- Some shower filters include a Kinetic Degradation Fluxation (KDF) process media aid to control this build-up.
- Other shower filters use silver technology that, when in contact with moisture, release silver ions and silver nanoparticles that prevent bacterial DNA replication and will kill microbes (and remove bacteria from the shower filter).
- The pressure and speed of the water flow in the shower allows no time for the carbon filter to react.
There are a few other factors that influence the effectiveness of your filtration system in fighting potential pathogenic microorganisms in your water supply.
These include the pore size of the filter, and the particle size and amount of the contaminant.
The smaller the pores, the smaller the contaminants they can remove.
Check the filter’s “absolute pore size” to calculate the smallest contaminant they can work with.
Using an absolute less than or equal to 0.3 micron filter offers moderate effectiveness when fighting harmful cysts and bacteria.
You should also check the NSF certification to see what the filter is certified to protect you against.
NSF/ANSI 53 is the standard applicable to water treatment units that establishes the minimum requirements for systems designed to reduce specific health related contaminants.
Filters for home use that comply with these standards can control microbial volatiles, cysts and lead.
Shower filters that can remove or reduce bacteria in water
Currently, shower filters that can effectively remove or reduce waterborne bacteria are few and far between.
We were able to find one shower filter with the adequate technology to kill bacteria, and three shower filers that are capable of controlling the growth of biofilms (removing and reducing bacterial populations in shower water).
These filters are available from Amazon.
Berkey Inline Shower Filter
The Berkey Inline Shower Filter uses their proprietary filter media that kills bacteria and also inhibits the further growth of bacteria, algae, and fungi.
While these Berkey shower filters contain bacteriostatic media, they do not carry NSF/ANSI certifications.
They do this because they believe the testing regime conducted by third-party accredited laboratories are more advanced than what is required to obtain the regular NSF-42 or -53 certifications.
They are also effective at removing 95% of chlorine from water and reduces levels of hydrogen sulfide (cause of rotten egg smells), iron, and scale build up in your shower.
This shower filter will filter a massive 20,000 Gallons of water before needing to be replaced.
The Berky Shower Filter is an excellent choice for any home and is effective at killing and controlling bacteria.
CraterAquaSystems Shower Filter
The CraterAquaSystems shower filter is effective at removes bacteria in two ways. First, it includes a KDF-55 filter that inhibits the growth of bacteria, fungi, and algae. Second, it has a SILVER layer that helps remove bacteria, protozoa some viruses.
The KDF-55 filter is a high-purity granulated zinc and copper alloy that is designed to reduce bacteria, algae and fungi in water. It also helps reduce water soluble heavy metals such as lead, nickel, chromium and mercury.
Silver is a well-known antibacterial agent.
The silver layer works by inhibiting bacteria from replicating, which reduces their population in water (and your shower filter). Silver Ions and nanoparticles prevent bacterial DNA replication as they bind to the cell membrane – eventually killing the microbe.
The 15-stage shower filter is also excellent at removing over 97% of chlorine thanks to the calcium sulfite layer, even at high temperatures.
You can expect anywhere an ~12,000 Gallons filter-life before needing to be replaced but like any filter, it will depend on the quality of water coming out of your taps.
Overall, the CraterAquaSystems shower filter is an excellent shower filter that removes bacteria and other nasties from water.
PurRite Shower Filter
PurRite Shower Filters contain KDF-55 media and nano silver to effectively removes bacteria and inhibits the further growth of fungi, algae and mold.
Silver acts as a powerful antibacterial agent that not only inhibits the growth of bacteria but also kills the microbe population over time by preventing DNA replication.
Coupled with the KDF-55 media, this PurRite Shower filter is effective at removing bacteria and many other biological nasties from water.
This 15-stage filter technology also removes chlorine, fluoride, heavy metals, odors and scale buildup.
It will filter approximately 10,000 -12,000 Gallons of water, depending on your regular tap water quality.
AQUAYOUTH Shower Head Filter
The AQUAYOUTH 2.0 Shower Filter prevents bacterial growth.
This shower filter has also been thoroughly tested in Korea to effectively remove chlorine (99%) and a suite of heavy metals including mercury (100%), iron (100%), lead (63%), and copper (33%). It also removes rust, sand and sediment.
Many of these contaminants, especially chlorine, can irritate the skin and eyes and cause issues to hair.
This filter will not last as long as some of the others on our list, with an approximate 3,500 Gallon filter-life.
How Can I Remove Bacteria From My Water?
Bacteria can be removed from your drinking water by distillation, reverse osmosis systems that have semi-permeable membranes with 0.0001 micron pores, and sub-micron water filter pitchers.
Water Purification Guide has more information about removing bacteria from your drinking water available here.
Final words
The risk of getting sick from exposure to microbiologically contaminated water in the shower is low.
Bathrooms are great environments to grow pathogenic microorganisms. Even if you install a totally effective and complex filtration system, bacteria thrive in shower enclosures, including showerheads, trays, floors, and curtains.
For that reason, additional measures should be taken to reduce the risk of exposure to bacteria in the shower:
- Flushing showerheads if they have not been used in a while (a week or more).
- Cleaning, disinfecting and maintaining your showerhead and shower curtain.
- Keeping private water sources safe, and staying updated with your water utility’s reports.
