Not Created Equal: Comparison of Water Filters

Selecting the right water filter for your home is a crucial step in your detox journey. As we know, heavy metals, agrochemicals, pharmaceuticals, and persistent pollutants have a way of making it into our water supply. The accumulation of these exposures contribute to a host of chronic health conditions over time. We can lessen our accumulation of toxic compounds by adding a water filter to our homes.

Isn’t City Water Already Filtered?

If your water comes from the city then it has already been filtered using one or more methods. However, contaminants still exist by the time the water gets to your faucet. This is because many chemicals are not currently regulated in tap water, such as pharmaceuticals, pesticides, and microplastics. Furthermore, each city uses different methods for treating water, and some contaminants may not be completely removed or treated by every treatment plant. Lastly, some pollutants can enter the water between the treatment plant and your home. This is possible if you have old water pipes made from lead or copper that then leach into your water. Contamination also happens if you have corroding or leaking water pipes that then allow naturally occurring compounds in your local soil to enter the pipes, such as arsenic.

To start you on our journey, here’s a comparison of four common types of water filters, detailing how they work and what contaminants they can (and cannot) remove:

Activated Carbon Filters

How They Work: These filters use activated carbon to absorb impurities. Activated carbon is organic material with high carbon content (like wood, coal, or coconut shells). This material is heated to create charcoal. It is then treated to create a porous material that binds to certain toxins and impurities, pulling them out of the water. 

Contaminants Removed: Effective against chlorine, volatile organic compounds (VOCs), pesticides, chloroform, lead, and mercury. It also improves the taste and odor of water. A specific type of activated carbon, called granular activated carbon, can further remove pharmaceuticals and PFAs.

Contaminants NOT Removed: These filters are not designed to eliminate bacteria and viruses, nor any arsenic, fluoride, nitrate, or perchlorate. Microplastics can be removed depending on their size, but they are not very effective.

Reverse Osmosis (RO) Systems

How They Work: RO systems are top of the line filters that remove a large percentage of water contaminants. They work by forcing water through a semi-permeable membrane,  allowing water molecules to pass through while rejecting contaminants based on size and charge. RO systems are the only water filter that also removes helpful electrolytes (minerals and salts) such as sodium, chloride, calcium, magnesium, and potassium. It is best to replenish these electrolytes in your water by applying trace mineral drops to your glass.

Contaminants Removed: Highly effective at reducing metals such as lead, mercury, cadmium, arsenic, hexavalent chromium, and copper. It also removes chlorine, fluoride, nitrates/nitrites, perchlorate, PFAs, VOCs, pesticides, pharmaceuticals, microplastics, and radium. Lastly, RO systems remove many bacteria and viruses, making them one of the most comprehensive options available. 

Contaminants NOT Removed: RO systems have difficulty removing dissolved gases like carbon dioxide, methane, radon, and hydrogen sulfide. It also can have trouble removing some types of pesticides. Bacteria and viruses can build-up on the filter and deteriorate the membrane over time. As long as the filter is replaced regularly, RO systems are effective at removing these microorganisms.

NOTE that reverse osmosis filters use a lot of water, wasting three to five times the amount of water that it treats.

Ion Exchange Filters

How They Work: These systems use resin beads that exchange harmful ions (like calcium, magnesium, and heavy metals) with safer ions like sodium or potassium. Ion exchange filters are most commonly associated with water softeners, although not always.

Contaminants Removed: Particularly effective for reducing heavy metals such as lead, mercury, cadmium, and inorganic arsenic. They also reduce nitrates and PFAs. As part of a water softener system, ion exchange filters reduce calcium and magnesium levels.

Contaminants NOT Removed: These filters are not effective at removing viruses, bacteria, or pesticides, and most types also aren’t very good at removing chlorine and fluoride.  

Ultraviolet (UV) Filters

How They Work: These systems use ultraviolet light to sterilize water by neutralizing bacteria, viruses, and other pathogens.

Contaminants Removed: UV filters kill microbiological contaminants, such as bacteria, viruses, and protozoa by damaging their DNA. Specific examples include E. coli, Salmonella, Mycobacterium tuberculosis, Giardia and Cryptosporidium, as well as fungi, algae, and cysts.

Contaminants NOT removed: While UV filters excel at disinfecting water, they do not remove chemicals, heavy metals, pesticides, or particulate matter. It’s best to use this filter in conjunction with other types of filters to remove prevalent contaminants.

Which Filter is Best for You?

Choosing the right filter depends on your water source and specific concerns. All drinking water has some kind of contaminants, but how much of which contaminants are in your water depends on where you live. Keep in mind that you can use a combination of these water filters to get the best results.

Before purchasing a water filter, it’s important to find out which “problem” contaminants are in your local drinking water. Tap water varies by region and depends upon its source. It could be treated for any number of contaminants, but not all of them. You can check your municipality’s Consumer Confidence Report which lists the levels of contaminants in your water and how they compare to the EPA’s standards for safe drinking water. As an alternative, The Environmental Working Group (EWG) has a helpful resource called the Tap Water Database. It’s a great place to get a basic understanding of your local water quality based upon your zip code.

 

Whether bottled, from the tap, or from a well, drinking water contains at least some levels of harmful toxins such as lead, mercury, “forever chemicals,” pesticides, pharmaceuticals, and microplastics. Continued exposure to these compounds can lead to a myriad of health problems, chronic disease, and cancer. Water filters ensure the removal of contaminants, although it’s important that your filter is targeting the contaminants that are actually present in your water. Choosing the right filter is key to having healthy water and a healthy life!