When ultraviolet (UV) light isn't busy killing waterborne pathogens, it's at the beach turning the shoreline into a bioluminescent light show. Some forms of plankton absorb UV light and then release it to create a fantastic, bright blue glow.
Filtration Technology
Pros and Cons of Each Type of Home Water Filter
5 min read
Some water filters remove every contaminant under the sun, some blast bacteria to smithereens, some improve the taste of your water, and some do it all.
This article gives a quick overview of the pros and cons of the most common types of water filters.
By the time you’re done reading, you should have a better idea of which filter is best for you and your family.
Let’s get to it!
We took the liberty of ranking the different types of filters from the most capable to the least capable of removing dangerous contaminants:
- Reverse osmosis (RO) systems: Remove 99.9% of contaminants and pathogenic microorganisms, soften “hard” water, balance pH and remineralize the water with essential electrolytes
- Ultrafiltration (UF) systems: Remove a large percentage of dangerous contaminants and bacteria, but cannot remove dissolved particles, “hard” minerals or fluoride
- Ultraviolet (UV) systems: Kill 99.9% of pathogenic microorganisms. They are usually combined with carbon filtration to remove chlorine, chloramine, trace heavy metals and several other contaminants
- Activated carbon filters: Remove chlorine, chloramine, trace heavy metals and several other contaminants
Now let’s take a closer look at the pros and cons of each type of filter…
Reverse osmosis (RO) systems stand out from the filtration pack because they can handle whatever pollutants flow their way.
It works by forcing pressurized water through a semipermeable membrane with very fine pores. Contaminants get trapped on one side and clean water flows through.
The Environmental Protection Agency states that reverse osmosis is “effective in eliminating all disease-causing organisms and most chemical contaminants.”
In addition, high-quality RO systems use a final remineralization phase to restore a healthy balance of minerals like calcium, magnesium and potassium.
- Removes 99.9% of harmful chemicals and pesticides
- Destroys 99.9% of pathogenic microorganisms
- Gets rid of disinfectants used at water treatment plants, like chlorine and chloroform
- Removes sediment and discoloration
- Protects your pipes from “hard” water
- Remineralizes with magnesium, calcium and other electrolytes
- Alkalizes and balances pH
- Improves taste
- Prevents “hard” minerals from gunking up, calcifying and staining appliances
- Easy to maintain
- Provides better water for cooking
- Produces more waste water than other types of filters
- May reduce water pressure
- Slows flow rate
- RO membranes can clog easily if not properly maintained
Ultrafiltration (UF) is a simple process to remove suspended contaminants from drinking water.
Similar to reverse osmosis, UF works by passing water through a semipermeable membrane. Unlike RO, it cannot remove dissolved contaminants, like pesticides and arsenic.
In commercial water treatment facilities, UF is often used as a pre-filter to separate particles from the water before treating it with reverse osmosis.
Lots of homeowners love UF systems because they consume less energy, require less water pressure, and produce less wastewater than RO systems.
- Kills 99.9% of pathogenic organisms, like bacteria and viruses
- Removes chlorine and chloramines (when combined with carbon filtration)
- Gets rid of most suspended (non-dissolved) contaminants, like lead, metallic trace elements (MTEs) and volatile organic compounds (VOCs)
- Removes sediment, rust and discoloration
- Consumes less energy than reverse osmosis
- Requires very little water pressure
- Easy to maintain
- Only removes suspended contaminants and bacteria
- Does not remove total dissolved solids (TDS), including dangerous pollutants like arsenic and pesticides
- Does not remove fluoride
- The UF membrane is easily damaged by oxidative chemicals like nitric acid
Ultraviolet systems are an effective way to kill pathogenic microorganisms, like Cryptosporidium, Giardia, Dysentery bacilli, Salmonella, Mycobacterium tuberculosis, Hepatitis B, and E.coli.
UV works by deactivating them with ultraviolet-spectrum light.
Stand-alone UV systems typically include a sediment filter and activated carbon filter. The sediment filter improves UV treatment by making the water less cloudy and the carbon filter removes chlorine and improves the taste and smell of the water.
The downside is that on its own, UV systems will still leave your family exposed to dangerous pollutants like arsenic and pesticides.
UV treatment is most effective when combined with reverse osmosis. Together, they can remove 99.9% of all contaminants.
Furthermore, RO with UV is ideal for private wells, where levels of chemical contaminants and pathogenic microorganisms are high.
- Kills 99.9% of pathogenic organisms, including viruses, bacteria, parasites, cysts and fungi
- Controls algae growth
- Removes bad tastes and odors (when combined with carbon filtration)
- Removes sediment, rust and discoloration (when combined with a sediment pre-filter)
- Produces zero wastewater
- Energy efficient
- Does not remove total dissolved solids (TDS), including dangerous pollutants like lead, arsenic, pesticides and nuclear waste
- Does not remove fluoride
- Heats the water, so tap water may come out slightly warmer than usual
Activated carbon, or charcoal, is a natural filter media that’s used as a pre-filter for most other systems, including UV, UF and RO.
Carbon filters are also sold on their own in a number of different forms, including:
- Water filter pitcher that fits in the fridge
- Faucet filter that attaches directly to the spout of the kitchen sink
- Under-sink filter that attaches to the cold water line
Furthermore, they’re great for improving taste and removing chlorine, bacteria and other basic contaminants. However, they won’t soften your water or remove pesticides and other dangerous pollutants.
- Removes disinfectants like chlorine and chloramines
- Gets rid of some carbon-based, organic chemicals
- Washes away trace amounts of some heavy metals, like copper, nickel, lead and cadmium
- Removes some microorganisms
- Improves the taste and smell of the water
- Affordable and easy to maintain
- Does not remove dangerous contaminants, like arsenic, pesticides and nuclear waste
- Keeps fluoride
- Weak against bacteria, viruses, parasites and cysts
- Does not remove “hard” minerals, like calcium and magnesium that can gunk up pipes and stain appliances
- Filters can quickly become ineffective with frequent use
Once-for-ounce, RO systems give you the most hardcore protection from 99.9% of contaminants.
Under-sink RO systems with remineralization cost between $300 to $800 and are easy to maintain. The only downside is that they produce quite a bit of wastewater compared to other systems.
However, ultrafiltration (UF) systems produce less wastewater and are a more eco-friendly option—just remember that they won’t be able to remove the most dangerous contaminants, like arsenic and pesticides.
Ultraviolet (UV) systems remove 99.9% of pathogenic microorganisms, but they can’t remove the most dangerous chemicals either.
Spring water is naturally alkaline. As rainfall flows over rocks and seeps through the soil, it picks up alkalizing minerals like calcium, magnesium and potassium. These minerals support nearly every organ in the human body. If you're going to install an RO filter, make sure it includes remineralization.
Activated carbon filters work great for removing chlorine and improving taste, but once again if you have serious contamination concerns you’re going to need an upgrade.
In addition, RO systems with remineralization can karate chop any contaminant and replenish your water with healthy electrolytes.
Cloud Water Filters feature built-in software that syncs to your phone so that you can monitor your water quality 24/7. It even tracks usage and automatically ships replacement filters right to your door.
You’ll never have to worry about water again!
Click here to learn more.
