Let it flow, let it flow, let it flow
There are 10 main types of water filters: mechanical, activated carbon, reverse osmosis, ion exchange, ultraviolet, ceramic, distillation, infrared, activated alumina, and microfiltration. If you’re looking to bring cleaner, fresher-tasting water into your home, a water filtration system is a good investment. However, with so many different types of water filters available, understanding your options can get a bit overwhelming. Read on to explore the basics of today’s most common water filters, including how each type works and its pros and cons.
A mechanical water filtration system uses a mesh barrier, screen, or porous material to prevent contaminants—like sediment, dirt, and rust—from entering your water supply. They have a micron rating that reflects how effective the filter is. Lower ratings equate to better particle-blocking capabilities.
| Pros | Cons |
|---|---|
| Moderately priced | Doesn’t get rid of chemicals |
| Easy to install and maintain | Filters need regular changing |
| Improves water clarity | Can’t remove microorganisms |
Best for: Filtering out visible debris and sediment
These water filters have a bed of activated carbon that traps chlorine and volatile organic compounds (VOCs). They can also remove some pesticides and heavy metals (including lead), but they don’t work on minerals, microbes, or salt. Like mechanical filters, activated carbon filters often serve as one of the first stages in multi-stage water filtration systems.
| Pros | Cons |
|---|---|
| Gets rid of pesticides, VOCs, and certain heavy metals | Can’t remove minerals, microbes, or salt |
| May improve water’s smell and taste | Not effective against inorganic pollutants |
| Fairly cost-effective and simple | Requires periodic filter changes |
Best for: Eliminating VOCs, chlorine, certain heavy metals, and pesticides
Reverse osmosis (RO) filters force water through a semipermeable membrane under high pressure. This process removes contaminants and impurities as small as an ion, including chemicals, microorganisms, dissolved salts, and heavy metals.
| Pros | Cons |
|---|---|
| Capable of removing most contaminants | Pricier than many other options |
| Can decrease water hardness | Wastes water |
| May improve water’s taste | Strips healthy minerals from water |
Best for: Producing ultra-clean drinking water that’s free from nearly all contaminants
Ion exchange filters swap hard water ions (such as calcium and magnesium) for softer ones (like sodium and hydrogen). They effectively serve as a water softener, which makes them suitable for areas with hard water. However, they can’t remove many types of contaminants, including bacteria, viruses, and VOCs.
| Pros | Cons |
|---|---|
| Reduces water hardness | Increases sodium levels in water |
| Limits limescale buildup in pipes and appliances | Doesn’t remove bacteria or organic contaminants |
| Blocks heavy metals | Expensive to run |
Best for: Minimizing scale buildup and softening hard water
When water passes through an ultraviolet (UV) filter, it’s sanitized by a UV light. This light damages the DNA of any microorganisms in the water, including bacteria and viruses, which disrupts their ability to reproduce and harm your health. UV filters are excellent for disinfection, but they’re most effective when paired with filters that can block other contaminants.
| Pros | Cons |
|---|---|
| Removes microorganisms | Doesn’t filter out chemicals or heavy metals |
| Energy efficient | Works best with clear water |
| Works without chemicals | Can’t remove particles |
Best for: Eliminating bacteria and viruses
Ceramic is a porous material, so when it’s used as a water filter, it can trap bacteria, parasites, and other contaminants. These cost-effective filters can be found in areas where waterborne diseases—like E. coli and salmonella—are a concern. However, their filtration capability is somewhat limited, so it’s best to use them in conjunction with other filters.
| Pros | Cons |
|---|---|
| Inexpensive | Not good for removing viruses, heavy metals, or chemicals |
| Works well against bacteria and parasites | Needs regular cleaning and maintenance |
| Suitable for remote or resource-limited communities | Slow filtration |
Best for: Filtering out bacteria and sediment in places with limited clean water
Distillation is a water purification system that involves capturing the steam from boiling water, then letting it cool and condense back into a liquid. As the vapor cools, it leaves behind many impurities and contaminants, including minerals, heavy metals, bacteria, and viruses. The result is a highly purified form of water, which is often used in laboratory and medical settings.
| Pros | Cons |
|---|---|
| Eliminates many contaminants | Expensive to run |
| Creates exceptionally pure water, no matter the quality of the source water | Time-consuming filtration process |
| Doesn’t use chemicals | Removes beneficial minerals |
Best for: Situations where ultra-pure water is necessary, like medical work
This type of water filter system uses infrared light to change the physical qualities of water, decreasing the size of the water molecules so that they’re more easily absorbed by the body. This process softens the water but doesn’t remove contaminants, so infrared filters should be integrated with other types for maximum filtration.
| Pros | Cons |
|---|---|
| Softens water | Doesn’t get rid of physical contaminants |
| Fairly easy to install and maintain | Pricey |
| Works with other types of filters | Newer filtration method with debatable effectiveness |
Best for: Pairing with other types of filters
As water moves through an activated alumina filter, certain contaminants—including arsenic, fluoride, and selenium—attach themselves to the alumina (aluminum oxide). It works much like an activated carbon filter, except it removes different contaminants. Before installing one of these filters, make sure you know how to dispose of them responsibly without harming the environment. If you have questions, contact a local water softener installation company.
| Pros | Cons |
|---|---|
| Blocks arsenic, fluoride, and selenium | Doesn’t filter out bacteria or many other contaminants |
| Relatively affordable | Water’s pH level impacts its effectiveness |
| Doesn’t remove beneficial minerals | Filter disposal can be tricky |
Best for: Regions where fluoride, arsenic, and selenium levels are particularly high
In a microfiltration system, water flows through a porous membrane, which captures large particles and certain microorganisms, including bacteria and some viruses. While they are energy-efficient and chemical-free, microfilters aren’t effective at removing chemicals or dissolved contaminants.
| Pros | Cons |
|---|---|
| Blocks solids and some microorganisms | Can’t filter dissolved contaminants, including salts and minerals |
| Doesn’t use chemicals | Pores are small and can get clogged |
| More energy efficient than many other filters | Installation can be expensive |
Best for: Filtering out bigger particles, bacteria, and certain viruses
One of the primary disadvantages of reverse osmosis filters is that they produce a significant amount of water waste. In fact, according to the Environmental Protection Agency (EPA), a point-of-use RO system wastes 5 gallons of water for each clean gallon it produces. An inefficient unit can waste 10 gallons per gallon of clean water.
According to the Centers for Disease Control and Prevention (CDC), there is no water filter or treatment system that removes 100% of contaminants. To find the best water filter for your needs, first decide which kinds of impurities or contaminants are most important for you to remove, then find a filter that’s effective in doing so. For example, if eliminating bacteria is your priority, you could consider a UV filter. Distilled water is the most pure form of filtered water available.
On average, a whole-home water filtration system costs between $1,100 and $3,500. However, the exact cost will depend on a few factors, including the type of filtration method. The most budget-friendly filtration systems include chemical injectors, which start at $600. Higher-end options, such as water distillers and reverse osmosis systems, range from $1,000 to $4,800.
