# Water Filter Nerd

The Water Filter Nerd Index
  
# Clean Water.Zero Guesswork.

  Water filtration analysis. Built for buyers who read the NSF listing.

  **strong** Cost per gallon hides behind cartridge pricing, and the listing number is the one line a buyer can actually check. **strong** No free products. No paid placements.

  
    [Find your filter in 70 breakdowns](#index)
    [How we score them](/methodology)
  

  
    
      136Listings tracked
      12Classes covered
      7Nerd Stamp™ criteria
      $0Paid placements
    
  
  
## Every Breakdown in the Index

  

  APEC4/7
  
    
### APEC Water Filters Review

    This APEC water filters review covers 3 records, from a 3 stage carbon unit to a 6 stage alkaline RO, and what each one prints. See our picks.

    [Open the APEC breakdown](/apec-review)
  

  Aquasana4/7
  
    
### Aquasana AQ-5300+ Water Filter

    Aquasana AQ-5300+ is WQA certified to NSF 42, 53 and 401 for its 78 contaminants, and the cartridge runs near 12 cents a gallon. See full specs.

    [Open the Aquasana breakdown](/aquasana-aq-5300-review)
  

  Aquasana4/7
  
    
### Aquasana AQ-5300+R Replacement Filter

    The Aquasana AQ-5300+R replacement cartridge is certified to 42, 53 and 401 for 78 contaminants, and it bills near 50 cents a gallon. See full specs.

    [Open the Aquasana breakdown](/aquasana-aq-5300r-review)
  

  Aquasana4/7
  
    
### Aquasana Water Filters Review

    Aquasana water filters review: 5 records from a $125 faucet filter to a $1,090 tank, one selective recipe and 78 named contaminants. See full specs.

    [Open the Aquasana breakdown](/aquasana-review)
  

  Berkey4/7
  
    
### Berkey Water Filters Review

    Our Berkey water filters review covers 4 gravity records on tank size, element life and certification. No listing numbers anywhere. See full specs.

    [Open the Berkey breakdown](/berkey-review)
  

  Alkaline4/7
  
    
### Best Alkaline Water Filters

    Only one of the 3 records puts a number on the pH it adds. The best alkaline water filters file the membrane standard instead. See our picks.

    [Open the Alkaline breakdown](/best-alkaline-filters)
  

  Baby Formula5/7
  
    
### Best Water Filters for Baby Formula

    Water for formula has to be low in lead. The best water filters for baby formula are the 3 records that name the right NSF standard. See our picks.

    [Open the Baby Formula breakdown](/best-baby-formula-filters)
  

  Apartments4/7
  
    
### Best Water Filters for Apartments

    The best water filters for apartments need no drill, no plumber, no landlord sign off. We compare 2 records that fit a rented kitchen. See our picks.

    [Open the Apartments breakdown](/best-apartment-filters)
  

  Budget5/7
  
    
### Best Budget Water Filters

    You do not need a big tank to drink clean water, and the best budget water filters prove it: 11 of these 16 name an NSF list. See our picks.

    [Open the Budget breakdown](/best-budget-filters)
  

  Camping5/7
  
    
### Best Water Filters for Camping and Emergencies

    Only 1 of the 22 records files a standard and 5 print a gallon rating. The best water filters for camping and emergencies need both. See our picks.

    [Open the Camping breakdown](/best-camping-filters)
  

  Chlorine Taste6/7
  
    
### Best Water Filters for Chlorine Taste

    Chlorine taste is the top reason people buy a filter. The best water filters for chlorine taste use plain carbon, 6 records deep. See our picks.

    [Open the Chlorine Taste breakdown](/best-chlorine-filters)
  

  Countertop4/7
  
    
### Best Countertop Water Filters

    The best countertop water filters need no plumber and no drill. We compare 7 records on tank size, filter life and cost per gallon. See our picks.

    [Open the Countertop breakdown](/best-countertop-filters)
  

  Faucet Mount6/7
  
    
### Best Faucet Mount Water Filters

    Get clean tap water in minutes with the best faucet mount water filters. We compare fit, flow, and filter life on all 8 models. See full specs.

    [Open the Faucet Mount breakdown](/best-faucet-mount-filters)
  

  Fluoride Reduction5/7
  
    
### Best Water Filters for Fluoride Reduction

    Fluoride is added on purpose, and the best water filters for fluoride reduction need a medium carbon cannot match. Six claim it. See our picks.

    [Open the Fluoride Reduction breakdown](/best-fluoride-filters)
  

  Fridge5/7
  
    
### Best Refrigerator Water Filters

    Compare the best refrigerator water filters by NSF certification, fit, and per gallon cost. OEM and aftermarket specs are reviewed. Find yours.

    [Open the Fridge breakdown](/best-fridge-filters)
  

  Gravity4/7
  
    
### Best Gravity Water Filters

    The best gravity water filters are 9 records running on one piece of physics: 5 steel tanks and 4 packable bags, and what each prints. Find yours.

    [Open the Gravity breakdown](/best-gravity-filters)
  

  Hard Water4/7
  
    
### Best Water Filters for Hard Water

    Hard water leaves scale and spots on the glass. The best water filters for hard water are the 3 records that name a real standard. See our picks.

    [Open the Hard Water breakdown](/best-hard-water-filters)
  

  High Flow4/7
  
    
### Best High Flow Water Filters

    Slow filtration kills daily usage. The best high flow water filters deliver clean water fast, reviewed by GPM and pressure drop. Compare now.

    [Open the High Flow breakdown](/best-high-flow-filters)
  

  Home Use4/7
  
    
### Best Water Filters for Home Use

    Find the best water filters for home use by water source, pipe age, and daily demand. Systems matched for apartments, houses, and wells. See reviews.

    [Open the Home Use breakdown](/best-home-water-filters)
  

  Inline4/7
  
    
### Best Inline Water Filters

    The best inline water filters splice into a fridge, ice maker or bottle filler line. We compare 5 records and their cents a gallon. See our picks.

    [Open the Inline breakdown](/best-inline-filters)
  

  Kitchen Sink5/7
  
    
### Best Water Filters for Kitchen Sink

    The kitchen sink is the busiest tap in the house. The best water filters for kitchen sink are the 3 records built for that draw. See our picks.

    [Open the Kitchen Sink breakdown](/best-kitchen-sink-filters)
  

  Lead Removal5/7
  
    
### Best Water Filters for Lead Removal

    Lead climbs in from the last few feet of pipe, so the best water filters for lead removal are bought on the number 53. Five file it. See our picks.

    [Open the Lead Removal breakdown](/best-lead-removal-filters)
  

  Long Life5/7
  
    
### Best Long Life Water Filters

    The best long life water filters trade a bigger cartridge for fewer swaps, and this shelf runs 3 months to 5 years on a promise. See our picks.

    [Open the Long Life breakdown](/best-long-life-filters)
  

  Microplastics5/7
  
    
### Best Water Filters for Microplastics

    The word is on 4 boxes and the pore size on 2. The best water filters for microplastics sort on the 1 number a particle obeys. See our picks.

    [Open the Microplastics breakdown](/best-microplastic-filters)
  

  NSF Certified5/7
  
    
### Best NSF Certified Water Filters

    NSF is not one badge, it is 6, and the best NSF certified water filters print 1 to 3 of them at a time, and 473 is on no box here. See our picks.

    [Open the NSF Certified breakdown](/best-nsf-certified-filters)
  

  PFAS Removal4/7
  
    
### Best Water Filters for PFAS Removal

    Only 3 of these 5 listings file the standard behind the claim, and the best water filters for PFAS removal file the paperwork. See our picks.

    [Open the PFAS Removal breakdown](/best-pfas-removal-filters)
  

  Pitcher5/7
  
    
### Best Pitcher Water Filters

    Compare the best pitcher water filters by contaminant removal, cartridge life, and cost per gallon. Spec reviews on 18 models. See our picks.

    [Open the Pitcher breakdown](/best-pitcher-filters)
  

  Portable5/7
  
    
### Best Portable Water Filters

    The 20 records split 5 squeeze against 5 gravity and only 1 files a standard. The best portable water filters are read on the label. See our picks.

    [Open the Portable breakdown](/best-portable-filters)
  

  Renters6/7
  
    
### Best Water Filters for Renters

    The best water filters for renters screw onto a spout and unscrew when you leave. We compare 3 fixtures on price and cartridge life. See our picks.

    [Open the Renters breakdown](/best-renter-filters)
  

  Cartridges4/7
  
    
### Best Replacement Filter Cartridges

    Replacement cartridges are where the real cost lives. We compare OEM and aftermarket by NSF certification, fit, and per gallon cost. See reviews.

    [Open the Cartridges breakdown](/best-replacement-cartridges)
  

  Osmosis4/7
  
    
### Best Reverse Osmosis Systems

    The best reverse osmosis systems strip water to near zero TDS. We review tanked, tankless, and remineralizing models on every spec. See our picks.

    [Open the Osmosis breakdown](/best-ro-systems)
  

  Sediment5/7
  
    
### Best Water Filters for Sediment Heavy Water

    Cloudy water is grit, rust and silt, and the best water filters for sediment heavy water sort it out before the carbon sees it. See our picks.

    [Open the Sediment breakdown](/best-sediment-filters)
  

  Under Sink5/7
  
    
### Best Under Sink Water Filters

    The best under sink water filters deliver clean water on tap with zero clutter. Spec reviews on lead removal, flow, and install. See our picks.

    [Open the Under Sink breakdown](/best-under-sink-filters)
  

  UV Purifiers4/7
  
    
### Best UV Water Purifiers

    The best UV water purifiers use light rather than carbon, and only 1 of 5 names a standard. We break down flow, lamps and bands. See our picks.

    [Open the UV Purifiers breakdown](/best-uv-purifiers)
  

  Full Index6/7
  
    
### Best Water Filters

    The best water filters ranked across pitchers, under sink, RO, and whole house. Full spec breakdowns on removal, flow, and cost. See our picks.

    [Open the Full Index breakdown](/best-water-filters)
  

  Well Water4/7
  
    
### Best Water Filters for Well Water

    Well water carries what city treatment never touches. The best water filters for well water handle iron, bacteria, and sediment. See our picks.

    [Open the Well Water breakdown](/best-well-water-filters)
  

  Whole House4/7
  
    
### Best Whole House Water Filters

    Filter every tap with the best whole house water filters. We review sediment removal, flow rate, and maintenance on 11 systems. See full specs.

    [Open the Whole House breakdown](/best-whole-house-filters)
  

  Brita5/7
  
    
### Brita Everyday Elite Pitcher

    Brita's Elite filter removes 99 percent of lead over 120 gallons, at about 15 cents a gallon. The bill is two cartridges a year. See full specs.

    [Open the Brita breakdown](/brita-everyday-elite-review)
  

  Brita6/7
  
    
### Brita Faucet Mount Filter

    The Brita faucet mount holds NSF 42, 53 and 401, a published 0.58 gpm flow and 100 gallons a cartridge for about 15 cents a gallon. See full specs.

    [Open the Brita breakdown](/brita-faucet-mount-review)
  

  Brita4/7
  
    
### Brita Replacement Filter

    Brita's Original filter is rated 40 gallons and runs near 13 cents a gallon in a three pack. Its data sheet names standards 42 and 53. See the data.

    [Open the Brita breakdown](/brita-replacement-filter-review)
  

  Brita6/7
  
    
### Brita Water Filters Review

    Brita water filters review: 9 live records, 2 cartridge families and 1 zero shared across the line. Specs, lead and cents per gallon. See reviews.

    [Open the Brita breakdown](/brita-review)
  

  Brita4/7
  
    
### Brita Small 6 Cup

    The Brita Small 6 Cup holds 48 ounces and runs a 40 gallon cartridge, so the two month clock sets the real bill. Specs and score. See the data.

    [Open the Brita breakdown](/brita-small-6-cup-review)
  

  Brita4/7
  
    
### Brita Tahoe 10 Cup

    Brita Tahoe 10 Cup runs on a 40 gallon cartridge at about 13 cents a gallon, and its data sheet stops short of lead. Specs and score. See the data.

    [Open the Brita breakdown](/brita-tahoe-10-cup-review)
  

  Brita4/7
  
    
### Brita UltraMax Dispenser

    Brita UltraMax dispenser: a 27 cup tank holding a 40 gallon cartridge on a 2 month clock. Specs, cost per gallon and the score. See full specs.

    [Open the Brita breakdown](/brita-ultramax-dispenser-review)
  

  Choosing5/7
  
    
### How to Choose a Water Filter

    Start with your water report, not a brand name. This how to choose a water filter guide runs the 4 questions, in the order that decides. Start here.

    [Open the Choosing breakdown](/choose-water-filter)
  

  Clearly Filtered5/7
  
    
### Clearly Filtered Review

    Clearly Filtered review of 3 records: a 10 cup pitcher, a 3 pack and an under sink box, with the certification field left empty on two. See our picks.

    [Open the Clearly Filtered breakdown](/clearly-filtered-review)
  

  Culligan4/7
  
    
### Culligan Water Filters Review

    Culligan water filters review covers 4 records across faucet mount, inline and pitcher lines, compared on standards and capacity. See full specs.

    [Open the Culligan breakdown](/culligan-review)
  

  Maintenance4/7
  
    
### Water Filter Replacement Schedule

    A water filter replacement schedule is 2 numbers, not a date. How capacity and your daily draw set the interval, class by class. See the data.

    [Open the Maintenance breakdown](/filter-replacement-schedule)
  

  Filter Methods4/7
  
    
### How to Filter Tap Water at Home

    How to filter tap water at home runs from a jug on the counter to a membrane under the sink, and we rank all 5 by install and removal. See the data.

    [Open the Filter Methods breakdown](/filter-tap-water-home)
  

  Maintenance6/7
  
    
### Water Filter Troubleshooting

    Water filter troubleshooting starts with the symptom, not the model. How slow flow, leaks and bad taste each point to one stage. See the data.

    [Open the Maintenance breakdown](/filter-troubleshooting)
  

  TDS Reduction4/7
  
    
### Do Water Filters Reduce TDS

    Do water filters reduce TDS? Only a membrane or a resin actually moves the number, while 93 of 136 boxes never print it at all. See the data.

    [Open the TDS Reduction breakdown](/filters-reduce-tds)
  

  Bacteria and Viruses4/7
  
    
### Do Water Filters Remove Bacteria and Viruses

    Do water filters remove bacteria and viruses? Carbon does not. Ceramic, hollow fiber, RO and UV do, at different printed pore sizes. See the data.

    [Open the Bacteria and Viruses breakdown](/filters-remove-bacteria-viruses)
  

  iSpring4/7
  
    
### iSpring Water Filters Review

    This iSpring water filters review covers 7 models, from a 2 stage anti-scale unit to a 6 stage RO, and the gallons behind each. See our picks.

    [Open the iSpring breakdown](/ispring-review)
  

  Katadyn5/7
  
    
### Katadyn Water Filters Review

    Every record in this Katadyn water filters review prints a life figure, from 1,000 liters to 50,000, and no label names a standard. See full specs.

    [Open the Katadyn breakdown](/katadyn-review)
  

  LifeStraw5/7
  
    
### LifeStraw Water Filters Review

    Only 2 of the 4 models in this LifeStraw water filters review state a life figure and 1 label names a protocol. See what each files. See full specs.

    [Open the LifeStraw breakdown](/lifestraw-review)
  

  NSF Certifications5/7
  
    
### NSF Certifications for Water Filters

    NSF certifications for water filters are earned through a lab test and a listing, then re-checked each year. Here is how it works. See the data.

    [Open the NSF Certifications breakdown](/nsf-certifications-explained)
  

  PUR4/7
  
    
### PUR PFM350V Faucet Filter

    The PUR PFM350V faucet filter is tested to NSF/ANSI 42, 53 and 401 and runs about 14 cents a gallon on a 100 gallon cartridge. See full specs.

    [Open the PUR breakdown](/pur-pfm350v-review)
  

  PUR4/7
  
    
### PUR Water Filters Review

    PUR water filters review: 7 live records, 1 word on the box that decides the lead listing, and 3 gallon figures at the spout. See full specs.

    [Open the PUR breakdown](/pur-review)
  

  PUR3/7
  
    
### PUR RF-9999 Replacement Filter

    PUR's RF-9999 replacement filter is tested to NSF/ANSI 42, 53 and 401, rates 100 gallons each, and runs about 14 cents a gallon. Compare now.

    [Open the PUR breakdown](/pur-rf-9999-review)
  

  RO vs Carbon4/7
  
    
### RO vs Carbon Filters

    Carbon filters take chlorine and taste, a membrane strips nearly everything. Compare the RO vs carbon filters trade on removal and cost. See the data.

    [Open the RO vs Carbon breakdown](/ro-vs-carbon-filters)
  

  Sawyer5/7
  
    
### Sawyer Water Filters Review

    This Sawyer water filters review covers 3 models on one 0.1 micron membrane rated for 100,000 gallons and a cartridge you never rebuy. See our picks.

    [Open the Sawyer breakdown](/sawyer-review)
  

  Worth It5/7
  
    
### Are Water Filters Worth It

    Are water filters worth it? We count the upfront cost, the cartridges you rebuy and the gallons the boxes print, against bottled water. See the data.

    [Open the Worth It breakdown](/water-filters-worth-it)
  

  Waterdrop5/7
  
    
### Waterdrop 10UA Water Filter

    The Waterdrop 10UA is NSF 42 certified, rated 11,000 gallons, and runs under half a cent a gallon. The paperwork disagrees, though. See full specs.

    [Open the Waterdrop breakdown](/waterdrop-10ua-review)
  

  Waterdrop4/7
  
    
### Waterdrop 10UB Water Filter

    The Waterdrop 10UB adds a stainless faucet and a counter hole to the 10UA body. Same 42 and 372 standards, 8,000 gallons rated. See full specs.

    [Open the Waterdrop breakdown](/waterdrop-10ub-review)
  

  Waterdrop5/7
  
    
### Waterdrop 15UA Water Filter

    The Waterdrop 15UA is NSF 42 certified, rated 19,000 gallons, and runs near 0.18 cents a gallon. The interval is the real limit. See full specs.

    [Open the Waterdrop breakdown](/waterdrop-15ua-review)
  

  Waterdrop4/7
  
    
### Waterdrop FC-01 Faucet Filter

    Waterdrop's FC-01 faucet filter is NSF 42 certified and rated 320 gallons, the longest in the faucet class. The clock is the catch. See full specs.

    [Open the Waterdrop breakdown](/waterdrop-fc-01-review)
  

  Waterdrop5/7
  
    
### Waterdrop PT-07B Pitcher

    The Waterdrop PT-07B pitcher holds a 200 gallon cartridge at about 6 to 8 cents a gallon, the lowest in our pitcher records. See full specs.

    [Open the Waterdrop breakdown](/waterdrop-pt-07b-review)
  

  Waterdrop5/7
  
    
### Waterdrop Water Filters Review

    This Waterdrop water filters review counts 22 models on 6 shelves, with a standard number on 11 and nothing at all on the other 11. See full specs.

    [Open the Waterdrop breakdown](/waterdrop-review)
  

  ZeroWater4/7
  
    
### ZeroWater 10 Cup Pitcher

    The ZeroWater 10 Cup Pitcher is IAPMO certified for lead, chromium and PFOA/PFOS, yet it runs near a dollar a gallon. Specs and score. See full specs.

    [Open the ZeroWater breakdown](/zerowater-10-cup-pitcher-review)
  

  ZeroWater4/7
  
    
### ZeroWater Water Filters Review

    ZeroWater filters review: 5 stage pitchers hit 000 TDS with a meter to prove it. We weighed that purity against a fast burn. See full specs.

    [Open the ZeroWater breakdown](/zerowater-review)
  

  
## Start Here

  
    - The Nerd Stamp™ Methodology: how every product is rated 1 to 7 on seven verifiable criteria.

    - About Water Filter Nerd: who reviews these filters, and how.

    - Affiliate Disclosure: how the site is funded, and what never moves a score.