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The Best Water Filters for Coliform Bacteria

Fact checked by Stephen Conklin

best water filter for coliform bacteria

Families who want to safeguard their loved one’s health against E. coli and other pathogenic coliform infections must use only the best water filter for coliform bacteria. More than a quarter of a million Americans suffer from E. coli infections every year, not to mention the thousands of others getting sick because of other disease-causing coliforms.

Choosing the right coliform water filter boils down to one’s understanding of several product features. These characteristics allow potential buyers to narrow down their choices, making selection more convenient. The following water filter attributes are crucial to making the right decision.

  • Filtration Technology: Water filters for coliforms can feature different filtration or purification mechanisms. Most use ultraviolet light to kill the bacteria and other susceptible microorganisms, while other systems screen and trap harmful germs and compounds.
  • Filter Type: Some families only want safe drinking water, while others may need coliform-free water for the entire house. A point-of-use product is suitable for people requiring safe water only from a single source. A whole-house filtration unit is ideal for families who expect safe water anywhere in the house.
  • Contaminant Removal or Water Purification Capabilities: Water filters for coliform bacteria must kill or remove as many microorganisms as possible. The higher the product’s contaminant removal or water purification capabilities, the better the filter. For example, a unit that kills 99.99% of germs is better than one that can only eliminate 90% of microorganisms.

Other features can play a role in deciding which among the different coliform water filtration systems to buy. One can see these factors in each of the coliform water filtration units we reviewed and the comprehensive buying guide we prepared.

Top 1

Big Berkey BK4X2

Weight 8.8 Pounds
Material 304 Stainless Steel
Flow Rate 0.54 GPM

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Top 2


Weight ‎0.22 Pounds
Material BPA-free Material
Flow Rate 0.8 GPM

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Top 3


Weight 7.90 Pounds
Material 304 Stainless Steel
Flow Rate 12 GPM

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Table of Contents

Top 7 Water Filter for Coliform Bacteria Reviews

1. Berkey Big Berkey BK4X2 Water Filter

Berkey is one of the most trusted names in the water filter industry. That is why many households consider its BK4X2 Countertop Water Filter System the right water filter to remove coliform bacteria and other contaminants.

I adore this filter’s modern stainless steel housing construction. Not only does it look tough, but it also never leaks chemicals and other unwanted substances in the water.

This stainless steel container can accommodate 2.25 gallons of the purest and safest water one can drink. It can serve coliform-free and zero-contaminant drinking water to a family of four or sixteen.

Unlike other coliform-removing water treatment systems, I am surprised by this product’s ultrafiltration efficiency. It does not kill coliforms and other germs. However, it filters 99.9% of these bad living things and prevents them from reaching one’s glass of water.

Since it is a countertop unit, one can bring this to the picnic grounds or on a road trip. Families will never have to worry about pesticides, pharmaceuticals, organic substances, and other impurities from their water.

I also commend the company for adding a pair of purification elements and fluoride filters with each purchase. If one likes to keep fluoride in the water, one can choose not to use the fluoride filter as a post-treatment unit.

While I love this filter’s exceptional purification capability, I still find its price unjustified. For starters, its purification element requires replacement every 3,000 gallons. It also does not help that this product’s filtration rate is only seven gallons per hour or about 15 ounces per minute.
  • Removes 99.9% of coliforms and other water contaminants
  • Stainless steel component for safer water
  • Holds 2.5 gallons; can serve 4 to 16 people
  • Two purification elements and fluoride filters included
  • Convenient countertop design
  • No power consumption
  • Expensive for its filter lifespan
  • Modest filtration rate
I recommend this water purification system to anyone who wants a convenient way to ensure safe, coliform-free drinking water right on any countertop. One does not have to worry about power consumption with this product.

2. Express Water ROALKUV10M UV Water Filtration

I am not alone in wondering will reverse osmosis remove coliform bacteria? Thankfully, the Express Water ROALKUV10M Reverse Osmosis Water Filtration System gives a definitive answer.

This product is one of the most trusted water treatment systems I have ever seen. Most water filters I know only feature up to six stages. This unit has eleven elements to give modern households the safest, purest, and cleanest water they can ever have.

I love this system’s combination of reverse osmosis and UV light. Ultraviolet light kills the coliforms and other disease-causing organisms, while the RO element traps them within a chamber. One will never worry about TDS, pharmaceuticals, novel contaminants, and other compounds in the water ever again.

One issue with an RO system is that it removes everything, even beneficial minerals. I am proud of what the company included in this unit. Its alkalizing element adds healthy substances into the drinking water, giving everyone drinks they can enjoy.

I also appreciate the bonus faucet that delivers 0.8 gallons per minute. Its leak detection system is also a charm, saving families the hassle of constantly monitoring their water treatment system for integrity issues.

I only wish the company rated its filtration system for high-pressure water networks. This product can only handle a maximum of 80 PSI, whereas other filters can accommodate up to 150 PSI.
  • 11 filtration stages as a complete water treatment system
  • Combination of UV and RO technologies for efficient contaminant removal
  • Adds minerals back into water
  • Integrated leak detection system for effortless maintenance
  • High-flow faucet included for convenience
  • Value for money
  • Low maximum water pressure threshold
I do not mind this product’s price tag. With 11 filtration technologies and an exceptional coliform-removal capability, I think it is a steal. Anyone who wants only the healthiest and purest water to drink or use in their meals should get this product.

3. HQUA HQUA-OWS-12 Ultraviolet Water Filter

Families looking for the top-rated water purification system to kill pathogenic organisms in their well water can buy the HQUA HQUA-OWS-12. This product is one of the most advanced water sterilizers on the market.

I am blown away by this product’s ultraviolet assembly, consisting of a reactor chamber, a quartz sleeve, and the UV lamp. These components ensure efficient water purification. With coliform bacteria in well water UV light destroys their DNA, rendering them incapable of reproducing or causing harm to anyone.

This product can kill up to 99.99% of susceptible microorganisms, including bacteria, parasites, protozoa, and viruses. This whole-house water purification system is the ideal solution for families who want the safest possible drinking water from anywhere around the house.

I am glad the company uses 304 stainless steel for its UV reactor chamber, giving families peace of mind, knowing that no unwanted chemicals are present in their water. The premium-quality UV quartz also guarantees up to 90% ultraviolet light transmittance, improving its germ-killing abilities.

I also like its 40-watt rating, making it suitable for budget-conscious people. It translates to about 350 kW annually, running 24/7/365. It can cost an additional $46 to $47 to an average family’s monthly electric bill.

My concern with this product is its 365-day UV lamp service life. I only wish the company can extend the light’s lifespan to at least another year, matching the UV quartz’s 24-month service lifespan. Also, some folks may find its 3.2-feet power cord short. One must plan where to install this unit in the home.
  • 304 stainless steel UV reactor chamber and quartz sleeve
  • Kills up to 99.99% of harmful microorganisms
  • Guarantees up to 90% ultraviolet light transmittance
  • Ideal for whole-house applications
  • Low power consumption for energy savings (40-watt)
  • Short power cord
  • UV lamp lasts only a year
Regardless, I still think this UV water purifier makes perfect sense for households with existing water treatment systems. They can install the unit after their ordinary water filter to safeguard their water against disease-causing microbes.

4. Viqua D4 UVMAX Home Water Disinfection

Homes that require exceptional coliform bacteria treatment can consider the Viqua D4 UVMAX. This compact device not only inactivates diarrhea-causing coliforms. It also neutralizes other microorganisms in the water, giving households the chance to live healthily.

I am surprised by this product’s dual POU/POE design. Most purification systems only work either as a whole-house unit or an under-sink device. It helps that it has a sleek design, allowing households to install it under their sink or near their main water valve.

Like many UV systems, this device features state-of-the-art ultraviolet radiation technology that breaks the genetic bonds of microorganisms. E. coli, giardia, and other pathogenic coliforms will never find their way into the drinking containers of people who have this unit in their homes.

While this unit only delivers 9 gallons of water per minute, it is still higher than the 5 GPM of other brands. Families will never complain about how it takes a long time to fill a glass with safe, germ-free water.

I also appreciate the UV water sterilizer’s built-in replacement indicator. It is perfect for people who hate monitoring their filter status or those who have episodes of temporary forgetfulness.

Unfortunately, I do not recommend this product for households with water issues other than the presence of germs. It does not have a sediment filter or an ACF to remove other water impurities.
  • Dual POU or POE design for improved flexibility
  • Inactivates coliforms and other germs
  • High water flow rate for consumption
  • Sleek design for installation under sink or near valves
  • Integrated UV lamp replacement indicator for hassle-free maintenance
  • Not a complete water treatment system
Nevertheless, families who have an existing three-stage water filtration system should consider adding this product. Its coliform-killing capability is unimaginable, and its maintenance is effortless.

5. HQUA HQUA-TWS-12 Ultraviolet Water Filter

The HQUA HQUA-TWS-12 is an effective coliform-busting and microbial-killing sterilizer filter. It has a slightly more extended service life than the company’s other UV water purification system.

As a coliform bacteria water filter, I am speechless with its coliform-inactivating properties. It uses UV light to disrupt microorganisms’ DNA, robbing them of their ability to multiply. I can think of hundreds of different germs this technology can inactivate, giving families the safest and purest water they deserve.

This product features three elements that form its UV microbial-inactivation mechanism. There is a food-grade, premium-quality stainless steel chamber that houses the industrial-grade quartz sleeve. I like the sleeve because of its high transmittance capability, allowing the unit to kill as many microorganisms in the water as possible.

Inside the sleeve is the company’s all-new and improved UV lamp, lasting 9,000 hours. On top of that, one also gets an extra UV lamp and sleeve, delaying the next purchase by another year or two.

I love that this product does not hamper the water flow rate, giving households as much as a dozen gallons per minute. It is also more compact than other UV products on the market, making its assembly and installation a breeze even for newbies.

While I commend this product’s remarkable water sterilization capabilities, I find its price too steep, considering it is only a UV filter. One can spend about the same amount and enjoy the ROALKUV10M’s 11 filtration stages, complete with RO, UV, and alkalizing elements. People still need to install other filtration technologies to improve this unit’s overall water treatment capabilities.
  • Inactivates coliforms and other bacteria
  • Longer UV lamp service life
  • Stainless steel chamber and high-transmittance quartz sleeve
  • Fast flow rate
  • More compact size than other models for effortless installation
  • Extra UV quartz sleeve and lamp included
  • Expensive for its features
Despite this concern, this product remains an excellent option for those whose primary concern is coliform or microorganisms in their water.

6. iSpring UVF55FS Whole House UV Water Filter

The iSpring UVF55FS is an exciting solution for a coliform in well water treatment system. This device not only provides families with coliform-free drinking water. It also ensures zero-microbe drinks.

I find this UV filter’s design remarkable. I can say its stainless steel construction is more solid than other products with similar materials, making anyone feel confident about its quality. People will never fret about introducing chemicals or nasty tastes into their drinking water with this unit serving their homes.

I love its flow sensor switch, available in stop, move, and auto modes. Families will love this feature as I do because it gives them the chance to control the water purifier’s operation. The majority of UV filters I know only have an automatic flow sensor. One cannot manually override the system in case one needs to.

Killing coliforms is welcome news for many families. I also expect them to feel happier, knowing this device can also inactivate viruses, protozoa, and other microorganisms. At the very least, getting hospitalized because of water-borne diseases will be the least of their worries.

I also like this product’s water flow rating. With its 12 GPM performance, families will never complain about not having enough water in their homes. Its large-diameter ports also avoid substantial drops in water pressure, ensuring one gets sufficient water.

One must realize that this is a UV treatment system only. It does not have sediment or activated carbon filters to remove impurities other than microorganisms. The UV lamp also requires annual replacement, which can increase its overall operating cost.
  • Kills coliform bacteria and other germs
  • Three-mode flow sensor switch for improved system control
  • High flow rate for maximum water use
  • Minimum pressure loss for optimum water utilization
  • Premium-quality stainless steel construction for safety and durability
  • UV lamp requires annual replacement
  • Not a complete system
Nevertheless, I believe in this product’s coliform-inactivating capabilities. If one already has an existing water filtration system, adding this unit makes a lot of sense.

7. iFilters U200UV Ultraviolet UV Water Filtration

Any person wanting to know how to filter coliform bacteria in well water should consider the iFilters U200UV. This device is not the average coliform UV filtration unit we know. It also includes filter elements that remove sediments and other particles everyone knows are present in well water.

While this product pales in comparison to the ROALKUV10M’s dizzying 11 filtration stages, I think it works better than UV-only units. If one thinks about it, there is no need to install separate pre and post-treatment filtration elements. This device’s built-in filter membranes can trap particles as tiny as 0.7 microns in diameter.

If the germs are big enough, the membranes will trap them and never allow them to get into one’s glass of water. Asbestos, mold, and other impurities cannot pass through the system’s filtration elements.

I think the best part is this device’s ability to remove odor and taste molecules, giving people a refreshing drink. Making coffee, tea, or any other beverage will be a joy.

I am also glad the company included a stunning faucet and ensured that its product complies with FDA standards. Families will sleep better knowing they drank safe, germ-free, and contaminant-free water before going to bed.

My only concern with this product is its modest water flow rate that maxes out at 4 GPM. I know of products that can do 10 GPM. Some people may also not like the idea of replacing the filter elements every six to twelve months, although this is an industry average.
  • Three-stage water treatment system for better water purification
  • Traps 0.7 micron particles; removes asbestos, coliform, and other substances
  • Improves water’s aesthetic qualities for a better drinking experience
  • FDA compliant design for peace of mind
  • Designer faucet included
  • More affordable than some products
  • Short filter lifespan
  • Modest GPM rating
This coliform-inactivating product may not have a high water flow. However, a UV sterilizer and two industry-standard filtration technologies are enough to make it a terrific option for the modern family. It is also more affordable than some UV-only units.

What to Look for When Buying Water Filter for Coliform Bacteria


Shopping for a coliform filter is not as challenging as many people claim. One only needs a fundamental understanding of coliform bacteria removal in water and accurate information about the things to look for.

Filtration Technology

The gold standard for treating coliform and other microbes in water is by shocking the water source with chlorine. Unfortunately, this chemical can make water unpleasant to drink. That is why many homes opt to use a coliform in well water filter with other technologies. At least three water treatment technologies are at the forefront of coliform removal.

  • UV Sterilizers

In theory, one cannot classify this technology as a form of filtration. Coliforms and other microorganisms do not pass through a semipermeable membrane – a defining characteristic of a filter unit.

Instead, water containing coliforms and other germs pass through a cylinder irradiated with ultraviolet (UV-C) light. The radiation breaks the DNA strands of microorganisms, preventing them from making genetic copies. In a way, UV light kills the microbes.

  • Reverse Osmosis System

Instead of pushing water molecules through a membrane, an RO system forces particles through a layer and collects them in a chamber. It leaves behind water molecules, allowing them to continue their journey through the water distribution lines.

RO systems can remove particles as tiny as 0.0001 in diameter, making them the most efficient water treatment on the planet. Unfortunately, this ability comes with a price. Reverse osmosis units also remove beneficial minerals from the water, which can acidify the water and leave some people more vulnerable to mineral deficiencies.

  • Ultrafiltration Membranes

Some filtration products feature a membrane with microscopic pores, often as tiny as 0.001 microns in diameter. The average diameter of the E. coli bacterium is 0.5 microns, making ultrafiltration technologies exceptional in removing coliform bacteria.

However, one must understand that these filters do not kill microorganisms. They only trap these germs in the filter cartridge. Only UV purification technology can kill coliforms and other pathogenic microbes.

Filter Type

After deciding on the filtration technology, one must also decide on the device type. Water filters come in two general classifications: point-of-entry and point-of-use.

These filters are point-of-entry systems that people install after their home’s main water valve, before the water line branches into smaller distribution lines. It is suitable for families who want coliform removal for every faucet and water fixture in the house.

  • Under-sink Filters

A common point-of-use filter, under-sink filters are down-scaled versions of whole-house filtration systems. One can install these devices under any sink, although some products can also double as a whole-house, point-of-entry filter.

  • Countertop Filters

As the name implies, these devices sit on a table or countertop. Some products require connecting a filter tank to a sink faucet, while others require manual water refills. These devices are perfect for households that do not like making substantial changes in their homes, much less undergo complex installation.

  • Filter Pitchers

Does Brita filter remove coliform bacteria? What about Zero Water filter coliform removal ability? These are valid questions that people ask. Unfortunately, neither Brita nor Zero Water has the technology required to either inactivate or filter coliform bacteria.

For water filter pitchers to remove coliform in the water, they must have UV sterilization technology, reverse osmosis mechanism, or an ultrafiltration membrane.

Given the size of pitchers, the first two technologies are out of the question. Sadly, we do not know of filter pitchers with ultrafiltration membranes. Most of them only have activated carbon filters.

Contaminant Removal or Water Purification Capabilities

It would be best to check a product’s coliform removal capabilities. As much as possible, buy a product that can kill or remove as close to 100% of coliform bacteria as possible. For example, a filter with a 99.99% coliform removal effectiveness is better than a unit that can only remove 90%.

Potential buyers may also want to check what other microorganisms and water contaminants the product can remove. If it can also kill viruses, parasites, and protozoa, that device will be an excellent buy.

It is one thing for a company to claim its coliform reduction properties. It is another thing to have an independent laboratory to confirm these claims. Ideally, the product should have an NSF certification or any validation from a reputable water quality organization.

Cost of Operation

Ultraviolet water purifiers require electricity to power their UV lamps. That is why one may have to consider the product’s energy consumption. While a low-wattage device will give households the savings they expect, it would be best to determine if the unit’s affordability compromises its UV transmittance.

Some UV products run on 40 watts, although most units require 50 to 60 watts. It is wise to remember that these devices may have to operate 24/7. Hence, one must estimate the additional expenses on one’s electric bills before purchase.

For conventional filters, one has to consider the filter lifespan. Filtration membranes and elements have a definite longevity, often not lasting one year for filters and two years for other components. Regular maintenance can help extend these elements’ service life.

Coliform Removal or Complete Water Treatment System

One must also decide whether to get a dedicated coliform-eliminating filter or a complete water treatment system.

Families who already have an existing water filtration system may choose to buy a UV sterilizing unit and install it after their sediment pre-filter. Households that only require microbial elimination can also pick this option.

However, if one wants to eliminate all water contaminants – particles, microorganisms, CTO, toxins, heavy metals, and more – the best product to choose is a multistage filtration system. It would be best to pick one with UV treatment technology and a reverse osmosis element. One might also want to add an alkalizing or ion-exchange device to increase the water’s pH and mineral content.

Installation Ease

Most people do not like spending additional money on product installations. That is why it is wise to get a coliform treatment system one can install effortlessly. Some products come with easy-to-read installation instructions, complete with all the hardware one needs to set the system up. Other products come pre-assembled, fast-tracking the installation process.

However, one should always check hardware compatibility with existing water fixtures. For example, households with 1-inch water pipes should pick water filters with equal-sized ports. While buyers can always get a system of a different size, it often entails buying adapters.

Can You Shower in Water with Coliform


Yes, you can take a shower using water with coliform. However, you must avoid drinking the shower water to evade possible gastrointestinal complaints. The good news is that the risk of illness for showering is lower than drinking a full glass of coliform-containing water.

It is essential to distinguish coliform from E. coli and other non-fecal coliforms. According to health experts, coliform bacteria are present in mammalian digestive tracts. These organisms help in lactose fermentation.

On the other hand, Escherichia coli (E. coli) is a fecal coliform with no known physiological function on the mammalian host. While scientists consider E. coli to be a part of the digestive tract’s normal bacterial flora, these microorganisms can produce toxins that cause diarrhea, pneumonia, neonatal meningitis, urinary tract infection, bacteremia, and more.

While fecal coliform in water will not cause illness, their presence often indicates water contamination. It is possible that the water also contains other coliforms, such as E. coli, Klebsiella, and Enterobacter.

That is why removing coliform from well water is crucial. It would also be best not to drink this type of water.

What Do You Do if Your Well Tests Positive for Coliform

According to the Environmental Protection Agency, anyone who receives positive coliform bacteria in drinking water should collect samples for a repeat testing for total coliform within 24 hours of coliform discovery.

The agency discourages shock-treating the water source with chlorine before collecting source, routine, or repeat samples. The EPA allows shock-treating coliform-positive well water if the person has prior EPA approval.

One should observe the correct sample collection procedures to avoid getting false total coliform positive test results. The federal agency recommends running the tap for at least five minutes before collecting a sample. The sample bottle must also be sanitized and opened only when ready to obtain the water sample. Replacing the lid as soon as possible is also a must.

It may take some time for the laboratory to return a test result. If the family needs to drink water from the contaminated well, the Centers for Disease Control and Prevention recommends boiling the water for at least three minutes before consumption.

If one wants to learn how to get rid of coliform bacteria in well water, shocking the well with chlorine will kill the microorganisms. However, one must also determine the source of contamination.

How Can I be Certain that my Well Water is Safe for Drinking after Filtering It

The only way you can be certain that your well water is safe for drinking after filtering it is by getting several samples and having a trustworthy and certified laboratory test them.

According to the EPA, the US has one of the safest drinking water. Unfortunately, if you source your drinking water from a well, there is the risk of soil microorganisms and other substances leaching into the water.

While having an E coli water filter can help eliminate this bacteria, it may not remove other germs, heavy metals, and other potentially harmful compounds. That is why water treatment systems for coliform bacteria form part of a larger and more complex network of interrelated filtration and water purification methods. It is the only way you can feel confident about your drinking water’s safety.

If you still feel uncertain, you can always resort to the old-school method of boiling your drinking water. One to three minutes of a rolling boil is enough to kill viruses, protozoa, and bacteria.

Alternatively, you can add six drops of 8.25% unscented chlorine bleach for every gallon of drinking water. If you are using 6% chlorine bleach, you can mix eight drops of the solution for every gallon of drinking water.


The best water filter for coliform bacteria saves modern families from costly coliform-related consultations, treatments, hospitalizations, and rehabilitations. When one chooses correctly, the filter not only inactivates coliforms. It can also kill other microbes, such as viruses, protozoa, cysts, and other bacterial species.

Picking the right filtration system to address coliforms in the water boils down to one’s preferences regarding filtration technology, filter type, purification performance, and a few other factors.

5/5 - (2 votes)