Photo courtesy of Aquasana.
Many homeowners need a water filtration system, but the systems vary in cost and effectiveness. Here's a look the different types to determine which is right for your home.
"Whole house" water filters located along the main supply line treat all the water throughout your home, making it cleaner, healthier, and free from unwanted tastes and smells. A whole house water filtration system can protect against dangerous bacteria and remove minerals for softer hair and skin. Most whole house systems utilize various types of filters through several stages of filtration. Each filtration stage targets a different contaminant. You'll need to select a filter or whole-house system that targets the unwanted contaminants in your home's water, but there's no need to spend money on a type of filter you do not need.
A smart first step in selecting a system is to check your local water quality report to learn of any specific contaminants you need to address.
Here’s a rundown of the different types water filters offered as stages of filtration, or as add-ons of a whole house system.
Sediment filters Often the first line of defense against unwanted particles, sediment filters are usually included in the pre-filter stage of a whole house system and remove larger granular particles before the water gets filtered for chemicals and other contaminants.
Sediment filters remove dirt, rust, silt, clay, sand and other debris. Removing these particles before filtration also prevents clogging at other stages of filtration, which can extend the life of the system. Pros
Removes large particles in water
Fairly easy to install
Relatively low cost
Improves performance and longevity of the entire system
Cons
Replacements needed often
Does not remove chemicals, bacteria, or viruses
Activated carbon filters Activated carbon is derived from natural materials like charcoal. When water passes through the medium, it absorbs chemicals and releases clean into the water supply. Granular activated carbon (GAC) filters are commonly found in whole house filter systems because the loose carbon particles work efficiently with high water pressure.
Pros
Improves taste
Improves smell
Removes chemicals like chlorine
Relatively affordable
Cons
Doesn’t remove large particles like metal
Catalytic carbon filters
Catalytic carbon filters add gas processing at high temperatures to the process for activated carbon filtration to remove chloramines.
Pro
Removes chloramines
Cons
Doesn’t remove chlorine as well
Most heavy metals unaffected
Additional cost
KDF Copper-Zinc filters
Kinetic Degradation Fluxion filters, or KDF filters, use copper and zinc to provide additional support the other components of your home water filtration system. With the materials' natural antimicrobial properties, these filters control the release of microorganisms like algae into your water. A KDF-55 or KDF-85 filter is sometimes the final phase for a whole house water-filtration system.
Pros
Inhibits bacteria and algae growth
Improves taste and smell
Cons
Doesn’t fully remove biomaterials
UV filters UV filters use ultraviolet light to eliminate dangerous microorganisms such as E Coli, giardia, and other bacteria and fungi which can cause illness. These filters are often sold as optional add-ons, but may be necessary for people who rely on private well water.
Pros
Sterilizes up to 99.99% of bacteria and viruses and 99% of cysts
Annual lamp replacement is easy
No chemicals or particles used
Cons
Must remain connected to a power source
No removal of particles or chemical contaminants
Softeners and conditioners
Water softeners and conditioners are used in conjunction with whole house water filters to remove magnesium and calcium known to cause "hard water." These minerals can wreak havoc on a home’s plumbing and appliances.
Softeners: Utilize ion exchange, which requires salt, to swap the hard water mineral ions with ions from the salt. In addition to salt, softeners also require electricity and generate wastewater.
Salt-Free Conditioners: Utilize a scale control media to attract and neutralize mineral ions by forming small, harmless crystals. Salt-free conditioners are considered better for the environment because they require no electricity and produce no wastewater.
Pros
Prevents scale buildup by addressing hard water minerals
Protects pipes and appliances
Improves water texture
Improves laundry (less damage after washing)
Cleaner, streak-free dishes
Cons
No filtration of chemical contaminants
Can be expensive
Calcite filters
Calcite filters, AKA acid neutralizers, are used to balance the water’s pH levels using natural minerals.
Pros
Makes acidic water more basic for improved taste
Cons
Removes no contaminants, only changes pH level
Reverse Osmosis filters Reverse Osmosis filters are the most expensive type of whole house water filter but are seen as a single solution to most household water problems. Reverse Osmosis filters work by pushing water through a semi-permeable membrane at high pressure, allowing only clean water to pass into the household supply. These filters are commonly considered the most effective filtration method, but in some cases can actually remove healthy minerals, which negatively affect the water's taste. Some systems include a "remineralizer" that restores healthy minerals lost in the RO process. Due to the high cost of a whole house RO system, homeowners might consider an under-sink RO system located at the most commonly used faucet for drinking water.
Pros
Offers the most powerful form of filtration
Provides the best water for cooking and drinking
Cons
Expensive
Sometimes removes healthy minerals, negatively affecting the water's taste
Some systems create wastewater
As you can see, there are several types of water filters that serve different purposes. Consider the contaminants in your area and choose a system that offers the stages of filtration you’ll need for your home.