How to Choose the Best Water Filter for Your Home
You've already decided that you want to have some kind of water filter for your home. Am I right?
But maybe you're not sure what kind you want or need. I know it can be a little overwhelming.
So I've put together this guide to help you understand what the different options are and how to decide which one is best for you.
You'll find explanations of all the common types of water filter systems available for home use and things you should consider in making your decision. I hope you'll find it helpful.
3 Steps to Determine Which Water Filter is Best
There are three basic steps to making the right decision about your water filter.
Points to Consider
You'll want to keep these three things in mind while you're evaluating the different types of filters:
POE versus POU
In the broadest sense, there are basically two categories of water filters:
Whole House/Point of Entry (POE)
In other words, with POE, the water encounters a filtration system first thing when it enters your house. This is going to filter all of your water - all sinks, washing machine, bathtub, exterior spigots, etc.
I don't cover whole house filters in this blog.
Point of Use (POU)
With POU, the filtration happens where the water is actually being used. Some types are connected to the plumbing at a single location, like under a kitchen sink. A reverse osmosis system is one example.
Others are countertop units that need to be filled by hand. Pitcher filters, faucet-mounted filters, gravity filters, and distillers are types of POU filters.
Water Filter Technologies
There are quite a few water filtration technologies to choose from.
Each material and method has its own strengths and weaknesses and level of effectiveness. That's why it's important to know exactly what you're getting when you buy a water filter.
So, here's a list of the most common methods and a description of each. Some of them might be used as standalone filters, and some are combined with other technologies as part of a system.
Activated carbon can come from any kind of organic material that has a high carbon content. You'll often see carbon filters made from coconut shells, for example.
It's a porous material with a slight positive charge that attracts impurities and makes them adhere to the surface. This is called adsorption.
Not all carbon filters are equally effective, though. Some of them only get rid of chlorine and bad smells and taste. But others can remove a lot of different organic compounds like VOCs and radon.
Carbon does not work for inorganic compounds like fluoride, arsenic, heavy metals, and chromium-6.
There are two common types of carbon filters: carbon block and granular activated carbon (GAC).
Carbon block filters have a greater surface area, so they're generally more effective than GAC filters.
Because carbon filters collect contaminants, they eventually reach a saturation point and have to be replaced.
Ceramic filters have tiny holes that allow water through while blocking particles of dirt and certain contaminants. While they're effective for filtering out bacteria and protozoa, they're not able to block viruses or chemicals.
Sometimes ceramic filters are embedded with silver, which is a natural bactericide. That's to prevent bacteria and algae from growing on them.
As long as they don't get broken, ceramic filters can be used for years, so they're an economical choice.
Distillation works by boiling water and collecting the steam. As the water evaporates, the contaminants are left behind. When the vapor cools, it returns to liquid form.
Biological contaminants like bacteria and viruses are killed by the boiling.
There are a few VOCs that have a lower boiling point than water, so they're not removed by distillation. Most home distillers have a carbon filter to take care of those contaminants. The result is pure H2O with nothing else in it.
In reverse osmosis (RO), water is forced through a semipermeable membrane. This membrane will block any particles that are bigger than the water molecules.
An RO membrane will block bacteria, viruses, protozoa, and many chemical contaminants like arsenic, fluoride, lead, and nitrate. But it won't work on chlorine, VOCs, or trihalomethanes.
That's why reverse osmosis systems always combine an RO membrane with one or more carbon filters. Together, they make a complete purification system.
Ultraviolet (UV) light is used to disinfect water by killing bacteria, viruses and protozoa.
Well, it doesn't actually kill them. What it does is attack their DNA so they can't reproduce. Almost the same thing.
UV purification is usually paired with reverse osmosis or some other form of filtration.
Most Common Types of Water Filter Systems
In this section, I'm going to tell you about the different ways that filter systems can be set up. You might find one filtration technology used in several types of systems.
Faucet Mount Water Filter
Faucet-mounted filters are attached to the end of the faucet. You just take off the aerator and screw the filter on in its place.
There's usually some type of off/on switch so you can turn it on when you want filtered water and then turn it off for washing.
Most faucet-mounted devices use an activated carbon filter to improve the taste and smell of the water. Some models are able to remove other contaminants like lead.
- Simple installation
- Can switch between filtered and unfiltered water
- May slow down flow of water
- Doesn't work with all faucets
- Filters have to be changed often
Average price range: $15 - $50
For more information about choosing a faucet water filter, please see Faucet Mount Water Filters: Which One is Best?
Countertop Water Filter
A countertop system connects to the faucet, but the filter unit sits on the counter next to the sink.
Some models have an attached faucet, so you dispense the water right from the filter.
Others send the water back through the sink faucet, and you toggle the filtered water on and off using a switch.
Different models use different types of filtration. The simplest ones just use activated carbon, but there are others with multiple filters. You can even get countertop reverse osmosis filters!
So, of course, the types of contaminants removed can vary greatly from model to model depending on the type of filtration technology they use.
- Easy to install
- Can switch between filtered and unfiltered water
- Doesn't use up cabinet space under the sink
- Longer filter life than faucet mount
- Takes up counter space
- Sometimes doesn't attach to faucet and requires modification
Average price: $30 - $300
Want more information about choosing the best countertop water filter? Please see Your Guide to the Best Countertop Water Filters.
A water distiller looks a lot like a coffee maker. It sits on the counter, and it runs off of electricity.
It has two containers - a boiling container and a collection bottle of some sort.
To use it, you fill the boiler with tap water, put it in place in the unit, and push the start button. The machine does all the rest.
The process is slow. It can take between 3 and 6 hours to distill one gallon of water, depending on the model.
Home water distillers always have a small carbon filter to remove any VOCs that might be left in the water after distillation. It's possible that you don't even need that extra filter, depending on the quality of your tap water.
Some people don't like the fact that even good minerals are removed during distillation. This can be remedied by adding a pinch of salt or liquid minerals to the distilled water, if you like.
- No installation
- Easy to use
- Very slow
- Needs electricity
- Gives off heat
Pitcher Water Filter
Water filter pitchers are straightforward and simple.
They have a reservoir on top that you fill with tap water. The water drips down through the filter and collects in the bottom part of the pitcher.
You can find pitcher filters in all kinds of styles and colors. Most of them hold about 2 quarts, but some are bigger than that.
There's a wide range when it comes to effectiveness, so you'll want to be sure to take a close look at the specs if you're thinking about getting one.
All of them remove chlorine and bad tastes and smells at a minimum. But a few are more advanced and can remove things like lead, fluoride, VOCs, and pesticides.
You'll also want to pay attention to the price of the replacement filters and the filter life. Sometimes replacing the filters almost costs the same as buying a whole new pitcher.
Or you might find that it ends up costing more than a different, more effective type of filter.
- Different styles and sizes available
- No installation
- Have to refill frequently
- Most are hard to pour without spilling
- Filter replacement can get expensive
Average Price: $25 - $75
Gravity Water Filter
Gravity filters are countertop systems that you have to refill by hand. They're kind of like pitcher filters on a much larger scale.
But, they're much more powerful and effective than the majority of pitcher filters.
The system consists of two large chambers that nest together. The filters are in the top chamber, and sometimes in the lower one, too. You fill the top with water, and gravity pulls the water down through the filters into the lower chamber.
There's a spigot in the bottom chamber for dispensing the water.
Most gravity filters use either activated carbon or ceramic filters. Some manufacturers combine carbon with other materials to increase their effectiveness.
The most popular gravity filters are made of stainless steel. They're durable and they're portable, making them ideal for emergencies and for outdoor use, as well as for everyday use at home.
You'll also find that they remove a wide range of harmful contaminants from water. And, unlike other systems, you don't have to start with tap water. You can even put water from streams and ponds into them and end up with clean safe drinking water.
- No installation
- Can use any kind of water except salt water
- Filters last a long time
- Variety of sizes
- Have to refill
- Takes up counter space
Average Price: $200 - $400
Get more information about gravity filters here.
Under Counter Carbon Block Water Filter
These filters are connected to the water supply and are installed under the sink. They have their own faucet mounted next to the regular sink faucet.
When you turn it on, water flows through the activated carbon block filter and out the faucet.
Carbon block filters mostly just remove chlorine and make the water taste and smell good. Some brands are more effective than others and work on a wider range of contaminants.
- Doesn't take up much space under the sink and none on counter
- Long filter life
- Installation required; may need a plumber
- Limited effectiveness.
- Filter replacement can be a hassle.
Average Cost: $50 - $500 (plus possible installation fee)
See my review of the best under sink water filters for more details about this type of filter.
Under Counter Multi-Stage Water Filter
Multi-stage filters are hooked up to your plumbing, and they have their own dedicated faucet. That means you might need to hire a plumber if you're not comfortable trying to do it yourself.
They combine several different filtration technologies. That's why they're called "multi-stage".
Most of them include a reverse osmosis membrane plus two or more activated carbon filters.
Other options you might find are a UV filter for disinfection or a filter that adds minerals to the water. Sometimes you can buy a basic system and then add on more stages later if you want.
The contaminants that are removed vary from product to product, depending on the types and quality of filters they use. So you really need to look at each model's specs to see how effective it is.
I will tell you, though, that reverse osmosis systems are generally good at removing most kinds of contaminants.
- Constant supply of drinking and cooking water
- Can customize
- Doesn't take up counter space
- Long filter life
- Installation required; may need professional plumber
- Takes up space under sink
- Expensive replacement filters
Average Price: $200 - $500 (plus possible installation fee)
If you'd like more information about reverse osmosis systems, please see my article Best Reverse Osmosis Systems | Reviews & Ratings.
Testing and Certification
Sometimes you'll see water filters that are "NSF certified" or "tested to NSF standards".
What does this mean, and does it matter?
First, what NSF is:
NSF International is an accredited, independent third-party certification body that tests and certifies products to verify they meet (certain) public health and safety standards. Products that meet these standards bear the NSF mark. (link)
There is no requirement that water filters be NSF tested or certified. It is not a government agency and doesn't regulate anything. NSF testing and certification are strictly voluntary.
Most reputable water filter manufacturers do have their products tested by independent laboratories, and they're happy to share the test results with the public.
It's my opinion that examining independent lab test results is more important than seeing an NSF emblem on a product. NSF certification means that the product has passed the minimum standards set by NSF.
Some products far exceed that standard even though they haven't been tested by NSF itself.
Also, it's very expensive for companies to have their products NSF certified, so they may choose not to pursue certification.
When you see that a product is "tested to NSF Standards", that means that it has been tested using the same criteria. But, you don't know if it met or exceeded the standards, or if it even fell short. The only way to know this is to check the independent lab test results.
So, while NSF certification can be useful in determining the quality of a water filtration product, it's not the ultimate proof that the product is worthy of consideration.
To learn more about NSF certification for water filters, visit the NSF website here.
Congratulations if you made it all the way to here! That was a lot of information to take in!
Let me give you a quick summary of how to pick the best water filter:
- First, determine which contaminants you want to eliminate from your water.
- Next, estimate how much filtered water you'll need every day.
- Then, decide which types of filters will meet your needs.
- Last, take a look at your budget and buy the best one that you can afford.
If you still have questions, feel free to leave a comment and ask away. I'll do my best to answer as soon as possible.