# How to Choose a Water Filter

# How to Choose a Water Filter: Match the Filter to the Problem, Not the Hype

**strong** There are 4 of them, and they don't swap places: what is in the water, which standard covers it, which format fits the room, and what the part costs to keep. *em*

[Choose a Water Filter: Specs](#specs)
[How Water Filters Are Scored](#score)
[Choose a Water Filter by Source](#who)
[Water Filter Trade Offs, and How to Choose](#proscons)
[Choose a Water Filter on Budget](#cost)
[Water Filter Classes Compared, and How to Choose](#compare)
[Choose a Water Filter: Questions](#faq)
[Choose a Water Filter: Verdict](#verdict)

**strong** This article contains affiliate links. **strong** at *em*. **strong** retail prices move daily, so we quote ranges and send you to the live figure on the listing. **strong** *em* Every number on this page traces to manufacturer documentation or a certification record, held against the claims on the box. No free products, no paid placements, no manufacturer relationships. Scoring rules are public on our [methodology page](/methodology).

[](https://www.amazon.com/dp/B0B3BM3Z94?tag=waterfilternerd-20&linkCode=ogi&th=1&psc=1)

## How to Choose a Water Filter: Start With the Report

**strong** It lists what's detected and at what level, against the limit the law sets. A private well doesn't have a report, so a lab test stands in for it and runs under $50. *em*

**strong** Chlorine, lead, a PFAS notice, a hardness figure, a nitrate number: those are specific things. Specific things have standards. *em*

**strong** 42 covers taste and odor, and 53 covers lead, cysts and volatile compounds. 401 covers emerging compounds, and 58 covers a membrane.

*em*

**strong** Format follows the room rather than the water. A rental can't take a cabinet and a house doesn't need a jug. *em*

- The documentation problem, counted across the index: of the 136 records we hold, 73 name a standard, 45 publish a capacity, and 30 publish both.

- The serial nobody prints: 0 of those 136 records print a listing number a reader can key into a certifier's site.

- The report is the shortcut: 1 document names the contaminant, and the standard number is the only thing a box can say that can be checked.

- The 4 questions in order: what is in the water, which standard covers it, which format fits, and what it costs to keep.

Think of it this way

**strong** The list is written before the trip and it names the things that are coming. The case is chosen after, and only a case sized to the list is worth carrying. *em*

What the 136 Records Publish
Bars showing how many of the 136 records in the index publish each document: 73 name a standard, 45 publish a capacity, 30 publish both, and none prints a listing number.
What the 136 Records Publish
Records, of 136

- 0 35 70 105 140 names a standard publishes a capacity publishes both 73 records 45 records 30 records Read off the standards and capacity fields across the whole index. A fourth bar would be flat: no record in the catalog prints a listing number a reader can key in, so a standard name is the strongest document a box here carries. What the whole index publishes, counted once. The 30 records that print both are the shortlist any buyer should start from. What that adds up to at your tap: 2 figure on a box can be checked and 1 of them is rare, so the shortlist writes itself before you look at a price. Ask 4 questions in order and the shelf shrinks to a handful of bodies. See the 3 Standard Jug ## How to Choose a Water Filter Scorecard: 5 of 7 for the Default Every record in this index is rated 1 to 7 across seven verifiable criteria, with 1 point per criterion and no partial credit. The pick is Brita's Everyday Elite jug, the cheapest body here filing the taste list and the health list together, and its card is copied row for row from the review of that jug rather than rescored here. Five lines take a point and 2 sit at zero, and the 2 zeros are the rate and the filing. The jug names 3 standards and 3 certifying bodies. It prints 120 gallons and quotes a gallon figure. Then it stops short of a flow rate and a listing number. Both zeros are things a box could print tomorrow at no cost to the water. CriterionPointsEvidence Certified removal scope1 point42, 53 and 401 on one sheet, with lead, cadmium, mercury, asbestos, benzene and class I particulates named as reductions Certification and test transparency0 pointsThree standards and three certifying bodies named, and still no certificate or listing number printed Filter life and rated capacity1 point120 gallons and 6 months, both published, the longest rated life in this brand's pitcher range Cost per gallon1 pointAbout 13 to 17 cents, near the bottom of the pitcher class Flow rate and pressure drop0 pointsNo flow rate published for the body or the cartridge Install and footprint1 point10 cups on one fridge door shelf, no plumbing, no tools and no presoak Maintenance burden1 pointTwo cartridges a year behind a reminder light on the lid, and hard water shortens the interval The 5 points are the ones this guide sorts on, and the 2 zeros are why the shortlist is 30 records long rather than 136. What the spec sheet will not tell you: the difference between a 5 and a 7 is a document, not a cartridge. The scoring rule treats a missing listing number as a transparency gap rather than a fault, which is why it costs 1 point. Any body on the 30 record shortlist is a defensible answer to the first 2 questions. The rest of this page is about questions 3 and 4. See the 8,000 Gallon Cabinet ## Choose a Water Filter by Source and Contaminant Question 1 lands you in 1 of 4 situations, and each 1 has a format that fits. A treated city supply with a taste issue, a treatment plant with a notice, a private well, and a building old enough to have lead in the joints. The water source picks the shortlist before the budget does. A taste problem with nothing named is the cheap end. A pitcher or a spout unit carries 42 and turns the water around for under $50. The chlorine shelf ranks that group. Add a name to the list and the filing has to move up to 53, which is where a pitcher with a health claim takes over. A name that a carbon block can't hold is where the format changes. Fluoride, nitrate and dissolved solids are jobs for a film, and the membrane comparison draws that line in full. A private well adds bacteria and sediment. That is why the well water roundup starts with a test rather than a body. An old building flips the order: lead comes before taste. A 53 filing is the floor there, and the lead shelf sorts on it first. Replace the fixture and the filter still holds the first pour of the morning, the strongest cup you'll draw all day. #### This Is Not Your Guide If You want a brand recommendation first: the order here is report, contaminant, standard, then body.

- You want to skip the report: a smell is not a name, and a filter bought against a smell is a guess with a logo.

- You want 1 answer for every house: the format follows the room, and a rental and a house don't get the same body.

The short version

**strong** Nobody picks a bolt by its color, and nobody should pick a filter by its packaging. *em*

[See the Membrane 6 Stage](https://www.amazon.com/dp/B00NWZ1RCK?tag=waterfilternerd-20&linkCode=ogi&th=1&psc=1)

## Choose a Water Filter: What You Get at Each Band

**strong** A spout unit needs none. A cabinet wants a place under the sink and about half an hour, and a whole house body wants a plumber and a shutoff. *em*

**strong** A 40 gallon cartridge and a 200 gallon cartridge can cost the same at the till. A year later, they're 5 times apart. *em*

#### What You Get

- A shortlist of 30 records out of the 136 that publish both a standard and a capacity.

- Four questions that narrow the shelf in about 10 minutes, using 1 free document.

- A format for every room, from a jug on a fridge shelf to a body on the incoming line.

#### What It Costs You

- About 10 minutes with a water report before any shopping, and a lab test under $50 on a well.

- A commitment step with every format: no tools at the low end, a plumber at the high end.

- The running cost, which the shelf price hides and the cartridge band reveals.

Put another way

**strong** A 120 gallon part on a 6 month clock is the calendar, not the gallons, in most houses. *em*

The [same 7 criteria](/methodology) score every record here, whatever the format.

[See the Spout Fixture](https://www.amazon.com/dp/B01GABXWCK?tag=waterfilternerd-20&linkCode=ogi&th=1&psc=1)

## How to Choose a Water Filter on Budget: Bands and Running Cost

**strong** The shelf doesn't show you the second 1. A jug costs under $50 and about 13 cents a gallon to run.

A cabinet runs about $70 to $250 up front. A membrane body starts near $240.

*em*

*em* the dearest body on a shelf is not always the dearest gallon, and a cheap part can cost more over a year than an expensive one. 240 gallons a year at 13 cents is about $31 of cartridges. The same year at 110 cents is roughly $400. *em*

- Under $50: the jug band, and the only 1 that needs no install, no tools and no counter space beyond a fridge shelf.

- About $70 up to $250: the cabinet band, where the health list and the widest filings live.

- About $240 and up: the membrane band, tanked first and tankless after it.

- About $115 to over $1,000: the whole house band, which is a plumbing decision rather than a drinking one.

- The running cost: 13 cents against 110 cents in the same format.

**strong** A [budget roundup](/best-budget-filters) sorts that shelf on the standard rather than the price. *em*

[See the Whole House Set](https://www.amazon.com/dp/B0779G2676?tag=waterfilternerd-20&linkCode=ogi&th=1&psc=1)

## How to Choose a Water Filter, Class by Class

**strong** Every class carries a different share. The spread runs from 3 in 4 down to none. *em*

ClassAnswersInstallTypical bandPublishes a capacity

**strong**The drinking tapScrews onunder $50**strong**
Under sinkThe kitchen tap, hiddenDIY, some drilling$70 to $25010 of 22
RefrigeratorThe dispenser and the iceNoneunder $604 of 11
Replacement cartridgeThe part you rebuyNoneunder $20 to about $1854 in 11
PitcherTaste and the light health listNoneunder $506 of 18
Whole houseEvery tap and the showerA plumberabout $115 and up3 of 10
Reverse osmosisDissolved solidsFaucet and a drain lineabout $240 and up0 of 18

**strong** The spout class is the best documented here and the membrane class the worst. Neither fact says what either removes. *em*

Capacity Published, by Class
Bars showing the share of each class that states a gallon figure, as a percentage: the spout class at 75 percent, cabinets at 45, refrigerators at 36, replacement parts at 36, jugs at 33, whole house bodies at 30, and membranes at none.
Capacity Published, by Class
Percent of the class

- 0 25 50 75 100 faucet mount under sink refrigerator replacement parts pitcher whole house reverse osmosis 75 percent 45 percent 36 percent 36 percent 33 percent 30 percent none Counted per class, so the bars compare shares rather than totals: 6 of the 8 spout bodies print a capacity and 0 of the 18 membrane bodies do. How well each class documents itself. The best documented class is the cheapest to install, and the least documented is the most capable. The pitcher class, the faucet mount group and the under sink cabinets each hold their own rows in full, and the membrane class is where the 0 comes from. See the Pocket Squeeze ## Choose a Water Filter: Questions to Ask What should I check first before buying a water filter The water report. Every municipal system publishes 1 each year and it lists what was detected against the legal limit, which turns a vague worry into a named contaminant. Which standard should I look for on the box Whichever 1 covers the name in your report. That's 42 for taste and odor, 53 for lead and the health list, 401 for emerging compounds, and 58 for a membrane. A box that files 2 of them has answered 2 questions. Do I need the most expensive filter No. 30 of the 136 records here publish both a standard and a capacity, and every 1 of them is a defensible answer for the water it was built for. Price tracks the format, not the water. How do I compare a pitcher with an under sink system Run the same 4 questions against both. The report picks the standard, and the room picks the format. A jug and a cabinet can file the same 3 standards and only 1 of them will fit a rental. How do I work out what a filter costs to run Divide the cartridge band by the rated gallons, then check the replacement clock. A 120 gallon part on a 6 month interval retires on the calendar in most houses, so the interval decides more often than the capacity does. ## Choose a Water Filter: Where the Shortlist Lands The pick is Brita's Everyday Elite jug, and it's the shortest honest answer to all 4 questions. It files 42, 53 and 401, rates 120 gallons, runs about 13 to 17 cents a gallon and sells under $50 with no install at all. No flow rate, no listing number. It's the default for a treated city supply with a name in the report. For a kitchen tap with a health claim, the under sink group is the format. 10 of its 22 records state a capacity. For a name carbon can't hold, the membrane class takes over. For a private supply, the well water page starts with the test. For a rental, the renter roundup keeps the commitment at zero. Four questions, 1 free document and a shortlist of 30 of the 136. Read the report first, name the contaminant second. Then let the standard and the room decide the rest. The main filter index ranks every record on the same 7 lines, and the high flow roundup covers the 1 performance figure this page leaves out. Open the Default Pick ### Run the Questions in Order Four questions, and the first 1 is a free document most people never open. Name the contaminant before the brand. A filter with the wrong standard won't fix your water. Check the Cabinet Format ## Choose a Water Filter: Every Term Named Here Water quality report: the annual document a municipal system publishes, listing what was detected and at what level against the legal limit. It's free and it's the first question.

- NSF/ANSI 42: the taste and odor list, covering chlorine and the compounds that carry a smell.

- NSF/ANSI 53: the health list, covering lead, cysts and volatile organic compounds.

- NSF/ANSI 401: the emerging compounds list, covering a set of pharmaceuticals and personal care residues.

- NSF/ANSI 58: the membrane standard, filed by reverse osmosis bodies.

- Listing number: the serial a certifier publishes for a certified model, which is what lets a reader confirm the exact unit. No record in the catalog prints 1.

- Rated capacity: the gallons a cartridge is rated for, and the bottom half of the cents per gallon fraction.

- Replacement interval: the clock a maker puts on a part, which retires it earlier than the capacity does in most houses.

- Cents per gallon: the cartridge band divided by the rated capacity, which is the only figure that makes 2 boxes comparable over a year.

- Certified against compliant: a certified body carries a listing from a named lab, and a compliant 1 only claims to meet the standard.

## Keep Reading: How Water Filters Get Chosen

- The Full Filter Index: all 136 records, ranked on the same 7 criteria this page uses.

- Best NSF Certified Water Filters: what each standard number covers, in full.

- RO vs Carbon Filters: the 2 technologies side by side, when a carbon block is not enough.

- Best Water Filters for Lead Removal: the shelf that sorts on the health list first.