Aquasana Rhino EQ-1000 Replacement Filters: Pre-Filter, Post-Filter, Tank and Cross-Fits
The Aquasana Rhino EQ-1000 takes an EQ-304 pre-filter every 2 months, an EQ-PFC.35 post-filter every 6 months and an EQ-1000R tank at 1,000,000 gallons or 10 years.
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Short answer
The Aquasana Rhino EQ-1000 (numbered WH-1000 on Aquasana’s current product page) has three replaceable parts. The sediment pre-filter is Aquasana’s EQ-303 3-pack in 10 in or EQ-303-20 in 20 in, sold on Amazon as the EQ-304 4-pack, and Aquasana’s replacement pages say to change it every 2 months. The post-filter is the EQ-PFC.35, a 10 in polishing cartridge Aquasana says to change every 6 months. The main tank is the EQ-1000R, rated by Aquasana at 1,000,000 gallons or 10 years; the smaller Rhino takes the EQ-600R at 600,000 gallons or 6 years. The optional salt-free conditioner is the WH-SFWC-S, rated at 1,000,000 gallons or 10 years. The one spec that must match on the pre-filter is 10 x 2.5 in (or 20 x 2.5 in), the standard slim housing size, which is why generic spun sediment cartridges fit and 4.5 in Big Blue cartridges do not. Aquasana publishes no micron rating for either cartridge.
What fits
Pre-filter, 10 in housing: the OEM part
Aquasana EQ-304, 4-pack
10 x 2.5 in polypropylene sediment cartridge; Aquasana says every 2 months, the listing 1 to 3; four per pack
Pre-filter, 20 in housing: the OEM part
Aquasana Rhino 20 in pre-filter, 3-pack
20 x 2.5 in polypropylene sediment cartridge; every 2 months; three per pack
Post-filter: the only OEM part for the position
Aquasana EQ-PFC.35
10 x 2.5 in twist-off polishing cartridge; every 6 months; required with the UV filter; one per pack
Cross-fit for the 10 in pre-filter housing
CFS spun sediment, 4-pack
9.7 in melt-blown polypropylene for standard 10 x 2.5 in housings (listing copy); not an Aquasana-certified part
The main tank, at 1,000,000 gallons or 10 years
Aquasana EQ-1000R tank
Sold by Aquasana direct at $1,898.00 on 12 September 2026; the EQ-600R (600,000 gallons, 6 years) fits the smaller Rhino
The pre-filter is a commodity 10 x 2.5 in cartridge and the cheapest part on this page; the part people get wrong is the tank, which Aquasana sells for $1,898.00 and which the 2-month pre-filter exists to protect.
Which cartridges fit the EQ-1000?
Aquasana’s Rhino product page now numbers the system WH-1000; the older owner’s manual and the Amazon listings for its parts still say EQ-1000, and the parts are the same. The pre-filter number drifted too: Aquasana’s own pages sell the 3-pack as EQ-303 (10 in) and EQ-303-20 (20 in), and the Amazon 4-pack of the same 10 in cartridge is labelled EQ-304 .
Buy by housing length. The installation kit decides whether the pre-filter housing is 10 in or 20 in, and a 20 in cartridge does not fit a 10 in housing.
| Part | Fits stage | Size | Manufacturer’s published figures | Link |
|---|---|---|---|---|
| Aquasana EQ-303, sold on Amazon as EQ-304 | Stage 1, sediment pre-filter, 10 in housing | 2.5 x 2.5 x 10 in (listing) | Replace every 2 months (Aquasana’s EQ-303 page); listing says 1 to 3 months, when the colour darkens or flow slows; no micron rating published | Aquasana EQ-304, 4-pack |
| Aquasana EQ-303-20 | Stage 1, sediment pre-filter, 20 in housing | 2.5 x 2.5 x 20 in (listing) | Replace every 2 months (Aquasana’s EQ-303-20 page); no micron rating published | Aquasana 20 in pre-filter, 3-pack |
| Aquasana EQ-PRE-204-R | Stage 1, the Low Maintenance pre-filter option | Not published | Aquasana’s Rhino page says it lasts 3 times longer than the standard pre-filter | Not linked: no listing opened |
| Aquasana EQ-PFC.35 | After the tank, sub-micron polishing post-filter | 2.5 x 2.5 x 10 in (listing) | Replace every 6 months, twist-off, no tools; required with the UV filter (Aquasana’s post-filter page); no micron rating published | Aquasana EQ-PFC.35, 1 cartridge |
| Aquasana EQ-1000R | The main tank | Not published | 1,000,000 gallons or 10 years; $1,898.00 on aquasana.com, 12 September 2026 | Aquasana direct only |
| Aquasana EQ-600R | The main tank of the 600,000 gallon Rhino | Not published | 600,000 gallons or 6 years; $1,427.80 on aquasana.com, 12 September 2026 | Aquasana direct only |
| Aquasana WH-SFWC-S | The optional salt-free conditioner tank | 32 x 46 x 9 in diameter | 1,000,000 gallons or 10 years; 15.3 GPM peak; $1,758.00 on aquasana.com (Aquasana’s conditioner page) | Aquasana direct; the older EQ-AST-WH-R tank on Amazon is rated 600,000 gallons or 6 years in its listing |
Two numbers from the brief this page was built on do not exist in Aquasana’s material. No Aquasana page or listing uses EQ-306 for the post-filter: the part is EQ-PFC.35. And the UV lamp for the well-water Rhino has no Aquasana spec sheet this page could open, so it is named here and not specified.
What else fits the same housing?
The pre-filter housing takes the standard slim cartridge, 10 x 2.5 in or 20 x 2.5 in nominal. The CFS listing for its spun sediment 4-pack gives a 9.7 in actual length and says it fits all standard 10 x 2.5 in housings, the same size class as the P5 and SDC-25-1005 cartridges. The 20 x 4.5 in Big Blue cartridges on the iSpring WGB32B and Express Water WH300SCKS pages are a different housing and do not fit.
| Alternative | Same size? | Rating (source) | What differs from the Aquasana part |
|---|---|---|---|
| CFS spun sediment, 10 x 2.5 in, 4-pack | 9.7 in actual, for standard 10 x 2.5 in housings (listing) | Graded-density melt-blown polypropylene; no micron figure in the listing title | Replaces the EQ-304 . Every figure is listing copy; CFS publishes no spec sheet. Aquasana’s listing says untested replacements are not certified for capacity or contaminant reduction |
| CFS pleated 0.35 micron, 4-pack | 9.75 x 2.75 in per listing, 0.25 in wider than the EQ-PFC.35 listing dimension | 0.35 micron pleated; about every 6 months (listing) | Offered for the post-filter position. The listing itself says to measure the current cartridge before ordering, and Aquasana’s post-filter page says the genuine part is required when the UV filter is fitted |
Aquasana publishes no micron figure for the post-filter. The model number carries .35 and the CFS listing calls its equivalent 0.35 micron, but no Aquasana document opened for this page states it, so this page does not either.
How often do they need replacing?
Aquasana’s replacement pages give 2 months for the pre-filter and 6 months for the post-filter. The EQ-304 listing stretches the pre-filter to 1 to 3 months and names the trigger: the cartridge darkens or the flow slows. Sediment load sets the real interval, which is why well owners on the sediment filter review put a coarser stage ahead of a cartridge like this.
The tank runs to 1,000,000 gallons or 10 years, whichever comes first, on Aquasana’s EQ-1000R page; the EQ-600R is 600,000 gallons or 6 years. Aquasana’s Rhino page rates the system at 7 GPM and 14.6 GPM peak, 100 psi maximum and 40 to 90 F; the flow rate calculator tells you whether your house draws more than the rated figure, which is the other reason a pre-filter clogs early.
Which part to buy
The Aquasana pre-filter carries no published micron rating and costs more per cartridge than the CFS spun cartridge that fits the same housing. What it carries instead is Aquasana’s line that untested replacements are not certified for capacity, which matters while the tank is inside its 10 years. For the OEM parts, fit the EQ-304 4-pack (or the 20 in 3-pack ) and one EQ-PFC.35 every 6 months. Skip the cross-fits if the UV filter is fitted: Aquasana’s post-filter page requires the genuine cartridge there. Skip this page entirely if the tank is past 10 years or 1,000,000 gallons; that money goes to the EQ-1000R at $1,898.00, or to a new system, and no cartridge changes it.
Frequently asked questions
Is the Aquasana EQ-1000 the same system as the WH-1000?
Yes. Aquasana's current Rhino product page numbers the 1,000,000 gallon system WH-1000, while the Amazon listings for its replacement parts and the older owner's manual still say EQ-1000. The replacement parts are the same either way: the EQ-303 or EQ-304 pre-filter, the EQ-PFC.35 post-filter and the EQ-1000R main tank.
Is EQ-304 the same pre-filter as EQ-303?
They are the same 10 in sediment cartridge under two numbers. Aquasana's own replacement page sells the 10 in 3-pack as EQ-303 and the 20 in 3-pack as EQ-303-20. The Amazon listing sells a 4-pack of the 10 in cartridge as EQ-304, at 2.5 x 2.5 x 10 in. Buy by length: a 20 in cartridge will not fit a 10 in housing.
What is the EQ-306 post-filter?
No Aquasana document or listing opened for this page uses the number EQ-306. The post-filter Aquasana sells for the Rhino is the EQ-PFC.35, a 10 in twist-off cartridge that its product page says to replace every 6 months and that is required when the system has the UV filter fitted. Treat EQ-306 as a third-party or legacy label.
How much does the Aquasana EQ-1000R replacement tank cost, and when is it due?
Aquasana's EQ-1000R page rates the replacement tank at 1,000,000 gallons or 10 years and listed it at $1,898.00 on 12 September 2026. The smaller Rhino's tank, the EQ-600R, is rated at 600,000 gallons or 6 years and was listed at $1,427.80 the same day. Both are sold by Aquasana direct; neither was found on Amazon.
Will a generic 10 x 2.5 in sediment cartridge fit the Aquasana pre-filter housing?
The Amazon listing for the Aquasana EQ-304 gives the cartridge as 2.5 x 2.5 x 10 in, which is the standard slim housing size, and the CFS cross-fit listing says its 9.7 in cartridge fits all standard 10 x 2.5 in housings. Aquasana's listing copy says untested replacements are not certified for capacity or contaminant reduction, so a generic cartridge is a warranty decision as much as a fit decision.
Sources
- Aquasana, Rhino Whole House Water Filter (WH-1000) product page
- Aquasana, 10 in Pre-Filter Replacement 3-Pack (EQ-303) product page
- Aquasana, 20 in Pre-Filter Replacement 3-Pack (EQ-303-20) product page
- Aquasana, Low Maintenance Pre-Filter Replacement (EQ-PRE-204-R) product page
- Aquasana, Post-Filter Replacement (EQ-PFC.35) product page
- Aquasana, Rhino 1,000,000 Gallons Replacement Tank (EQ-1000R) product page
- Aquasana, Rhino 600,000 Gallons Replacement Tank (EQ-600R) product page
- Aquasana, Salt-Free Water Conditioner (WH-SFWC-S) product page
