Point of Use Water Filter Types, Costs and How to Pick One

Some under-sink filters waste 10 gallons of water to make 1 gallon you can drink.

That’s the worst case the EPA reports for inefficient reverse osmosis units. The best ones waste 2.3 gallons or less.

So the filter type you pick matters. Here are the 5 types, what each removes and costs, and how to choose.

What Is a Point of Use Water Filter?

A point of use water filter cleans water at one fixture, usually the kitchen sink, instead of treating all the water entering your home. Under-sink units, countertop filters, faucet mounts, pitchers and water dispensers all count.

You clean the water for drinking, cooking and coffee, and leave the shower and washing machine alone.

A whole-house system, called point of entry (POE), treats the whole water supply where the main line comes in. Both are forms of drinking water filters and home water filtration, but they solve different problems.

How Does a Point of Use Water Filter Work?

A point of use water filter pushes tap water through one or more cartridges just before it leaves the faucet. Most systems pair sediment and activated carbon stages, and some add a reverse osmosis membrane or UV light to catch other kinds of water contamination.

Here’s what each stage does:

• Sediment: traps sand, rust and other impurities.
• Activated carbon: grabs chlorine and bad taste or odor.
• Reverse osmosis (RO): forces water through a semipermeable membrane, which splits it into clean water and reject water.
• UV: a UV water filter kills germs with ultraviolet light.

5 Main Types of Point of Use Water Filters

Point of use water filters come in 5 main types: under-sink carbon, under-sink reverse osmosis, countertop, faucet-mounted, and pitchers or dispensers. The right one depends on what’s in your water and whether you can plumb under the sink.

Under-Sink Carbon Filters

These use 2 or 3 carbon block and sediment stages under the cabinet, and you’ll need to install an under-sink filter on the cold line.

Under-Sink Reverse Osmosis

A membrane system adds an RO stage after the carbon, often with a tank and its own tap. It’s the only type that sends water down the drain.

Countertop Filters

A countertop water filter needs no drilling, and countertop reverse osmosis units bring the membrane without plumbing.

Faucet-Mounted Filters

A faucet mount screws onto your tap with a lever for filtered or plain water: no tools, no plumber.

Pitchers and Water Dispensers

Pitchers and water dispensers filter by gravity, so they’re the easiest swap for plastic bottles of water, but slow.

What Does a Point of Use Water Filter Remove?

What a point of use water filter removes depends on the technology inside it. Carbon mainly fixes taste, odor and chlorine, while reverse osmosis goes much further.

Point of use RO systems can potentially remove lead, VOCs, PFAS, arsenic, bacteria and viruses, according to EPA WaterSense.

But water filtration only removes what the filter is certified for. So look for a certifier like NSF International on the box.

A water filter for lead needs a lead claim on its certification, not just a promise of better water quality.

Point of Use vs Point of Entry: Which Do You Need?

Choose a point of use filter if you only need better water to drink and cook with. Choose a point of entry (whole-house) system if the problem reaches every tap, the shower and your appliances.

Want RO for drinking water and basic treatment everywhere else? Use both.

A whole-house filtration system also protects pipes and the water heater, which a single-tap filter never touches.

How Much Does a Point of Use Water Filter Cost?

A point of use reverse osmosis system can cost as little as $159.95. That’s the November 2026 price of the Brio Pure Alkafuse 6-stage RO system at HomePlus Products.

That sticker price is only part of the bill.

So sort a store’s water filtration section by price, shortlist 3 certified models, and add a year of cartridges to each.

How Much Water Does a Point of Use RO System Waste?

A typical point of use RO system dumps 5 gallons or more of reject water for every gallon of purified water it makes, the EPA says. WaterSense-labeled systems must keep that to 2.3 gallons or less per gallon.

Choosing a WaterSense model cuts water use by more than 3,100 gallons a year on average. That’s about 47,000 gallons over the life of the system.

If you’re set on RO, look for the WaterSense label first.

How Often Should You Change a Point of Use Filter?

Change point of use filter cartridges on the maker’s schedule, in gallons or months. A WaterSense-labeled RO membrane must last at least 1 year, the EPA minimum for that label.

Write the install date on each housing. Before you reorder, check the types of water filter cartridges yours takes.

How to Choose the Right Point of Use Water Filter

The right point of use water filter is one certified to remove what’s actually in your water, in a format your kitchen can hold. So learn your water quality before you shop.

1. Check your water. Read your city’s yearly water report, or test your well.
2. Match the technology. Carbon for taste and chlorine, a membrane for heavy metals like lead or arsenic.
3. Pick the format. Renting? Start with a countertop unit or a water dispenser.

A membrane isn’t always needed: EPA WaterSense says simple filtration that uses little or no water is sometimes enough.

Pull your water report this week. Then shortlist models certified for what’s in your drinking water.