AquaTru Replacement Filters: Classic, Carafe and Freestanding Filter Sets, Intervals and Cross-Fits

AquaTru Classic filters last 6 months/600 gal (Pre/Carbon), 2 years/1,200 gal (RO), 1 year/600 gal (VOC). Carafe filters are rated 300 gal and do not swap.

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Countertop reverse osmosis purifier with its replacement filter cartridges laid out on a bright kitchen counter

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OwnerSpec compares published manufacturer specifications, certification listings and sourced technical documents. Unless a page explicitly states otherwise, OwnerSpec has not laboratory-tested or used the products it compares. Editorial policy

Short answer

AquaTru sells two countertop filter sets that do not interchange. The AquaTru Classic (and the Connect and Under Sink units that share its cartridges) takes three filters: a Pre/Carbon filter in stages 1 and 2, replaced every 6 months or 600 gallons; a reverse osmosis filter in stage 3, replaced every 2 years or 1,200 gallons; and a VOC Carbon filter in stage 4, replaced every 1 year or 600 gallons, each interval per AquaTru’s own filter product page. The smaller AquaTru Carafe AT100 takes its own Pre/Carbon filter (6 months or 300 gallons) and VOC Carbon filter (1 year or 300 gallons), sold as separate SKUs. The Freestanding Model 1 relies on a visual filter monitor, and AquaTru publishes no gallon or month interval for it. AquaTru prints no part number on any filter page, so the spec that must match is the model family on the box. No manufacturer or regulator source names a third-party cross-fit for either set.

The picks

  1. Classic, Classic Smart or Under Sink: the 6-month change

    AquaTru Classic Pre/Carbon Filter (Stages 1-2)

    Single filter; 6 months or 600 gallons per AquaTru's product page; fills stages 1 and 2

  2. Classic, Classic Smart or Under Sink: the yearly change

    AquaTru Classic VOC Carbon Filter (Stage 4)

    Single filter; 1 year or 600 gallons per AquaTru's product page; the plain VOC, not the Alkaline Mineral Boost variant

  3. Carafe AT100 owners: one Pre/Carbon plus one VOC

    AquaTru One-Year Carafe Filter Combo Pack

    Combo pack, Carafe only; Pre/Carbon rated 6 months or 300 gallons, VOC 1 year or 300 gallons; a second Pre/Carbon is still due at month 6

  4. Carafe AT100 owners: the mid-year Pre/Carbon on its own

    AquaTru Carafe Pre/Carbon Filter (Stages 1-2)

    Single filter, Carafe only; 6 months or 300 gallons per AquaTru's product page; will not fit a Classic

Do not order a filter until you have read the model name on the machine itself: the Classic and Carafe cartridges are different sizes, and with no part number printed anywhere, nothing on the box will catch the mix-up for you.

Which filters fit the AquaTru Classic and Carafe?

AquaTru’s replacement-filters collection page splits its cartridges into five groups (Carafe, Classic, Under Sink, Shower and Freestanding Model 1) and states that replacement timing varies by filter and model. The table lists the two countertop sets by stage, with the interval and list price from each filter’s product page on 2026-09-14.

FilterFitsStageInterval (maker)Price (maker, 2026-09-14)Listing
Classic Pre/Carbon FilterClassic, Connect, Under Sink1-26 months or 600 gallons$29.95AquaTru Classic Pre/Carbon Filter
Classic Reverse Osmosis FilterClassic, Connect, Under Sink32 years or 1,200 gallons$59.95Not sold on Amazon as a standalone item; buy from aquatru.com
Classic VOC Carbon FilterClassic, Connect, Under Sink41 year or 600 gallons$39.95AquaTru Classic VOC Carbon Filter
Carafe Pre/Carbon FilterCarafe AT100 only1-26 months or 300 gallons$29.95AquaTru Carafe Pre/Carbon Filter
Carafe VOC Carbon FilterCarafe AT100 only41 year or 300 gallons$39.95Sold with the Pre/Carbon as the Carafe One-Year Combo Pack
Freestanding Model 1 filtersFreestanding Model 1 onlyNot itemised on the product pageNot published; visual filter monitorNot publishedNot listed

The Carafe’s stage 3 reverse osmosis filter is not itemised on AquaTru’s Carafe filter pages this session, so its interval is not printed here. The AquaTru Glass Carafe listing groups the Carafe, Carafe Alkaline and Carafe Smart together, and all three use the Carafe filter set.

What else fits the same machine?

Only AquaTru’s own cartridges, per every source available this session. The alternatives below are AquaTru’s own variants and the wrong-family mistakes, not third-party fits.

AlternativeFits?What differs
Alkaline Mineral Boost VOC Filter (Classic)Yes, in place of the stage 4 VOC Carbon filter, per the Classic product pageAdds magnesium and calcium back after the membrane. Skip it if you chose reverse osmosis to push TDS as low as it will go: see whether RO water needs remineralization
Carafe Pre/Carbon or VOC filter in a ClassicNoDifferent physical size; AquaTru sells the two sets as separate SKUs rated 300 gallons against 600 gallons
Classic filter in a Carafe AT100NoSame mismatch in the other direction
Third-party “compatible” cartridgeNone foundNo manufacturer or regulator source names one; resellers (Walmart, Home Depot, dealers) carry only AquaTru-branded filters
Freestanding Model 1 filtersFreestanding onlyAquaTru publishes no filter name, part number or interval for it; the unit runs on a visual monitor and is rated for 0.8 gallons per minute and over 25 people daily per its product page. Skip it for a single household: the Classic or Carafe covers normal home use with a published change interval

AquaTru’s warranty page says the standard warranty excludes filters and recommends genuine parts. No counterfeit-specific notice could be read this session, so any counterfeit claim you see elsewhere is unsourced.

How often do they need replacing?

AquaTru gives each filter a month figure and a gallon figure, due at whichever comes first. The condition that shortens the interval is consumption: a household that draws 600 gallons through a Classic in under 6 months changes the Pre/Carbon early, and the machine’s filter indicator, not the calendar, is the signal to follow.

FilterAquaTru’s intervalReached first when
Classic Pre/Carbon6 months or 600 gallonsConsumption above 100 gallons a month
Classic Reverse Osmosis2 years or 1,200 gallonsConsumption above 50 gallons a month
Classic VOC Carbon1 year or 600 gallonsConsumption above 50 gallons a month
Carafe Pre/Carbon6 months or 300 gallonsConsumption above 50 gallons a month
Carafe VOC Carbon1 year or 300 gallonsConsumption above 25 gallons a month
Freestanding Model 1Not published; visual filter monitorNot published

The gallon ratings set the running cost apart. At AquaTru’s list prices, a Classic Pre/Carbon at $29.95 for 600 gallons is 5 cents a gallon, and a Carafe Pre/Carbon at $29.95 for 300 gallons is 10 cents a gallon, so a Carafe household buying the same water pays twice as much on pre-filters.

A TDS meter reading that climbs with fresh pre-filters points at the reverse osmosis stage instead.

Which standards are the filters listed to?

AquaTru’s Classic product page lists the system to NSF/ANSI 42, 53, 58 and 401 with IAPMO as the certifying body, for 84 contaminants; that is the listing per the maker’s page, and the IAPMO R&T database was not queried this session. The Carafe filter pages say the unit is certified to NSF standards without breaking out the numbers.

The Freestanding Model 1 page lists NSF 42, 53 and 372 plus UL 399. What each standard covers is on the NSF/ANSI standards guide.

Which set to buy

The AquaTru cartridges carry no part number and no published third-party fit, so the only thing to check is the family name on your machine. The flaw to know before buying: the Classic reverse osmosis filter (stage 3, 2 years or 1,200 gallons) does not appear on Amazon under AquaTru’s brand, so a Classic owner buys the Pre/Carbon and VOC Carbon filters there and the membrane from aquatru.com.

A Carafe owner buys the One-Year Combo Pack and one extra Carafe Pre/Carbon for month 6, and should skip the Carafe set entirely if cost per gallon matters more than counter space: read the countertop reverse osmosis comparison before choosing.

Frequently asked questions

How often does the AquaTru Classic Pre/Carbon filter need to be replaced?

AquaTru's Pre/Carbon filter page gives a replacement interval of 6 months or 600 gallons, whichever comes first. The same cartridge fills stages 1 and 2 of the Classic, the Connect and the Under Sink unit. A household that drinks more than 600 gallons in 6 months hits the gallon limit first and changes the filter early.

How long does the AquaTru Classic reverse osmosis filter last?

AquaTru's Reverse Osmosis Filter page lists a lifespan of 2 years or 1,200 gallons for the stage 3 membrane in the Classic, Connect and Under Sink units. The maker price on that page is $59.95. AquaTru does not list this filter on Amazon as a standalone item, so it is bought from aquatru.com or a reseller.

Are AquaTru Carafe filters the same as AquaTru Classic filters?

No. AquaTru sells the Carafe AT100 filters as separate SKUs from the Classic set. The Carafe Pre/Carbon filter is rated 6 months or 300 gallons and the Carafe VOC Carbon filter 1 year or 300 gallons, per their product pages, against 600 gallons for each Classic equivalent. The two sets are not interchangeable between machines.

What NSF/ANSI standards is the AquaTru Classic certified to?

AquaTru's Classic product page lists NSF/ANSI 42, 53, 58 and 401 with IAPMO as the certifying body, covering 84 contaminants. That is the listing per the maker's page; the IAPMO R&T database was not queried this session. The Carafe filter pages say the unit is certified to NSF standards without breaking out the standard numbers.

Is there a third-party filter that fits an AquaTru?

No manufacturer or regulator source names a compatible third-party cartridge for the AquaTru Classic or Carafe. Resellers carry only AquaTru-branded filters, and AquaTru's replacement-filters collection page separates the Carafe, Classic, Under Sink, Shower and Freestanding Model 1 sets as five distinct groups. Per available sources, the genuine cartridge is the only fit.

Fact sheet and how to cite this page

Answer
The AquaTru Classic, Connect and Under Sink take a Pre/Carbon filter every 6 months or 600 gallons, a reverse osmosis filter every 2 years or 1,200 gallons and a VOC Carbon filter every 1 year or 600 gallons, per AquaTru’s filter product pages. The Carafe AT100 takes its own Pre/Carbon (6 months or 300 gallons) and VOC Carbon (1 year or 300 gallons) filters, and the two sets do not interchange.
Applies to
  • AquaTru Classic (also Connect, Under Sink)
  • AquaTru Carafe AT100
  • AquaTru Freestanding Model 1
Compatibility basis
AquaTru product pages for the Classic Pre/Carbon, Reverse Osmosis and VOC Carbon filters, the Carafe Pre/Carbon and VOC Carbon filters, and the replacement-filters collection page, read 2026-09-14
Assumptions
  • AquaTru publishes no part or SKU number on any filter page; filters are identified by model family and stage only.
  • NSF/ANSI 42, 53, 58 and 401 for the Classic and 42, 53 and 372 for the Freestanding Model 1 are listed per the maker’s page and were not checked against the IAPMO R&T listing this session.
  • Maker prices are AquaTru’s list prices on 2026-09-14 and will drift.
Method
Stage, fit, interval and price taken from each filter’s product page on aquatru.com; family separation confirmed on the replacement-filters collection page; each Amazon listing opened to confirm the title and pack.
Primary source
AquaTru: Classic Pre/Carbon Filter product page (manufacturer or vendor document)
Facts verified
Last updated
Cite as
OwnerSpec, "AquaTru Replacement Filters: Classic, Carafe and Freestanding Filter Sets, Intervals and Cross-Fits", https://ownerspec.com/water/parts/aquatru-replacement-filters-classic-carafe/, facts verified 14 September 2026.

Every figure above also appears, with its source, in the article. All sources ยท How OwnerSpec verifies numbers

Sources

  1. AquaTru: Classic Pre/Carbon Filter product page (manufacturer or vendor document)
  2. AquaTru: Classic Reverse Osmosis Filter product page (manufacturer or vendor document)
  3. AquaTru: Classic VOC Carbon Filter product page (manufacturer or vendor document)
  4. AquaTru: Carafe Pre/Carbon Filter product page (manufacturer or vendor document)
  5. AquaTru: Carafe VOC Carbon Filter product page (manufacturer or vendor document)
  6. AquaTru: Classic Countertop Reverse Osmosis Water Purifier product page (standards and stages) (manufacturer or vendor document)
  7. AquaTru: Freestanding Model 1 product page (manufacturer or vendor document)
  8. AquaTru: Replacement Filters collection page (manufacturer or vendor document)