PUR RF-9999 Replacement Filter: Three Standards on a Hundred Gallon Cartridge
The PUR RF-9999 Replacement Filter is the cartridge that keeps every PUR faucet mount running, and its paperwork is better than its economics. The performance data sheet names this exact cartridge model and says the faucet mount systems have been tested to NSF/ANSI 42, 53 and 401, with a 100 gallon capacity and a 0.52 gpm rated flow printed on the same page. Then the same manufacturer says three different things about who certified it: tested on the sheet, NSF and WQA on the storefront, IAPMO on the listing. A two pack covers 200 gallons for about $25 to $30, which is about 14 cents a gallon, and the cartridge ranked 1 in Replacement Faucet Water Filters on the day we last checked.
PUR RF-9999 Replacement Filter Specs: Two Cartridges, 200 Gallons
The PUR RF-9999 is the consumable half of every PUR faucet mount, sold as a two pack with a six month calendar attached to it. Model RF-9999, and the same cartridge is sold as a single, a two, a three, a four and a six pack, which tells you how the manufacturer expects you to buy it: in bulk, on a schedule.
For where the cartridge sits against the rest of the aisle, our faucet mount water filter rankings hold the running list, and the rest of the PUR lineup takes the same 100 gallon cartridge across every mount. Here is what the documents say, including the three that disagree about who certified it.
- Standards on the data sheet: PUR's performance data sheet says the faucet mount systems have been tested to NSF/ANSI 42 and 53, plus 401 and prints the reduction table for all three. That's a broader standard set than any other replacement cartridge we carry, covering taste and odor, the health list, and the trace compounds.
- The cartridge is named in it: the sheet is written for replacement filter models RF3375 and RF9999 by number, so the document is about this part rather than about a family of products.
- Rated capacity: 100 gallons per cartridge, from the sheet's own capacity line for faucet mount models. The two pack is therefore 200 gallons, which the listing describes as a six month value.
- Rated service flow: 0.52 gallons per minute for the faucet mount models the cartridge fits, which is about 67 ounces a minute. An eight ounce glass takes about seven seconds of filtered flow.
- Service interval: 3 months. PUR's support pages and the listing both say to change the cartridge every three months, and the housing carries a light that counts it down.
- Pressure and temperature: the sheet gives 20 to 100 psig working pressure and a usable water temperature of 34 to 82 Fahrenheit, so the cartridge runs on the cold side only.
- Which mount it fits: every PUR faucet filtration system, plus the Beautiful by PUR mounts, per the listing. The sheet's model list runs from the older FM units through the PFM numbers, so the fit is the product line rather than one model.
- Install: unscrew the housing from the faucet, twist off the back cover, drop the cartridge in, replace the cover. PUR's own instructions add a five minute flush before first use and five seconds of running water before each pour, and a three second press on the reset button to clear the light.
- What it does not do: the sheet's footnote says PUR does not filter microbes. Carbon and ion exchange chemistry is what this cartridge is, and disinfection is a different product.
- Price band: $25 to $30 for the two pack at our last check, in stock, sold and shipped by Amazon.com, buy box winner. That's about $12 to $15 per cartridge. Bands only, and the listing holds the live figure.
- Category position: rank 1 in Replacement Faucet Water Filters at our last check. The most bought cartridge in its category is not the same as the cheapest per gallon, which is the argument this page makes below.
- Not published: a certificate or listing number, a micron rating, and any reduction percentage for lead outside the data sheet table. Those gaps cost the transparency line, and one of them is the reason the page hedges on microbes.
What that adds up to at your tap: a filter the size of a coffee cup that handles a hundred gallons, three standards behind the reduction table, a light on the housing counting the days, and an errand every three months for as long as you own the mount.
A hundred gallons passes through a cartridge about the size of a coffee cup, which is roughly a thousand cups of water per cup of filter. Put differently, the cartridge is about 1.5 cups of material doing the work of 1,600 eight ounce glasses. That ratio is why the 3 month clock exists: a thousand to one is not a filter being lazy, it is a filter being small.
Think of it this way
A cartridge that fits is not a cartridge that is certified, and the difference is the plug on a charger. The shape of the plastic gets the part into your housing; the listing number is what happens inside it. The listing makes this point itself when it warns that off brand filters may fit but are not certified.
PUR RF-9999 Replacement Filter Score: 3 of 7
Every product in this index is rated 1 to 7 across seven verifiable criteria, one point each, with no partial credit. I am an enthusiast with a long memory and a spreadsheet, not a lab, and the scorecard below is the entire method in one table. The standards behind it are unpacked in our NSF certification guide.
Each line asks two questions: is the number on the record, and does it hold up against the rest of the class. The line stays at zero when the document is missing or the figure is the worst in its class. 4 of the 7 points are gone here, and the cartridge half of this aisle is where a small tank hurts most.
| Criterion | Points | Evidence |
|---|---|---|
| Certified removal scope | 1 point | NSF/ANSI 42, 53 and 401 with a reduction table for all three, the broadest standard set of any replacement cartridge in our records |
| Certification and test transparency | 0 points | No certificate or listing number, and three conflicting certification stories: tested on the sheet, NSF and WQA on the storefront, IAPMO on the listing |
| Filter life and rated capacity | 0 points | 100 gallons a cartridge, tied with the Brita faucet cartridge for the shortest tank in our faucet records |
| Cost per gallon | 0 points | About 13 to 15 cents, tied with the Brita cartridge at the top of our faucet records against about 4 cents for the FC-01 |
| Flow rate and pressure drop | 1 point | 0.52 gpm rated service flow and the 20 to 100 psig window, both published on the cartridge's own data sheet |
| Install and footprint | 1 point | Twist the back cover off, drop the cartridge in, press the light for 3 seconds. No tools and no counter space |
| Maintenance burden | 0 points | 4 cartridge changes a year for a household drinking a gallon daily, on the 3 month clock, tied with the FC-01 for the heaviest schedule in our faucet records |
Four lines sit at zero and the cartridge aisle is unforgiving. Two of them are the price of a small tank: a hundred gallons a cartridge and the cents per gallon that follow from it. The tank is what the mount's housing allows, and no amount of certification changes the volume.
The transparency zero is the one worth reading twice. This cartridge has a data sheet that names it by model number, which is more than most of the aisle manages, and the same company describes it as tested on one surface, certified by two named bodies on another, and certified by a third body on the listing. Three answers to one question is why the point isn't awarded, even though the paperwork here is thick.
Who This PUR Replacement Filter Fits
The question with a replacement cartridge is never which one is best. It's whether the one you're holding fits the body you already own. This cartridge answers that question for one product line and one line only, and everything else on the page follows from the 100 gallon tank it holds.
Pick your side. If the mount is already on your tap, this is the part that keeps it working.
- The PUR owner: every PUR faucet filtration system and the Beautiful by PUR mounts take this cartridge, and the sheet's model list covers the older FM numbers as well as the current ones.
- The household that drinks a gallon daily: two cartridges is roughly six months, which is why the pack is sold in that shape.
- The person who wants the health list covered: standard 53 includes lead and mercury, and 401 adds the trace compounds, which is a wider set than the pitcher cartridges in our records.
- The bulk buyer: PUR sells this as a single, a two, a three, a four and a six pack. The larger packs are the tell about how often the manufacturer expects you back.
- The careful refiller: the flush and reset instructions are short and published, so the cartridge's first five minutes are documented rather than guessed.
This Is Not Your Cartridge If
- You do not own a PUR faucet mount. This cartridge fits one product family, and no adapter makes it fit another.
- You want the cheapest gallon in the aisle. The wider tank one aisle over runs about 4 cents a gallon against about 14 here.
- You want a lower maintenance count. A 200 gallon cartridge in the same category needs about 2 changes a year against 4 for this one.
- You expect microbe removal. PUR's data sheet says it doesn't filter microbes.
- You are chasing a certificate number. Three surfaces disagree about the body, and none of them prints a number.
The way I see it
A replacement cartridge is a subscription to a device you already paid for. The mount was a one time decision and the cartridge is the part that repeats, 4 times a year, for as long as the housing holds. Buying the two pack is not a saving so much as an acknowledgment of the schedule.
PUR Replacement Filter Pros and Cons
What You Get
- The widest standard set in its aisle: 42, 53 and 401 with a printed reduction table for each, which no other replacement cartridge we carry matches.
- A data sheet that names the part: RF3375 and RF9999 are both written into the sheet, so the document is about this cartridge rather than the family.
- A published flow rate: 0.52 gpm and a 20 to 100 psig window, which the pitcher cartridges on file mostly leave out.
- A twenty second swap: twist the back cover off, drop it in, reset the light with a three second press.
- Two cartridges per pack: six months of drinking water at a gallon daily, and a larger six pack if you would rather shop once a year.
- The top seller in its category: rank 1 in Replacement Faucet Water Filters, which is the practical answer to availability.
What It Costs You
- A hundred gallons a cartridge: tied for the shortest tank among the faucet cartridges we carry.
- About 14 cents a gallon: roughly three and a half times the Waterdrop cartridge that does the same job on the same faucet.
- A cartridge every season: the 3 month clock, not the capacity, is what retires it in an ordinary household.
- Three certification stories: tested on the sheet, NSF and WQA on the storefront, IAPMO on the listing, and no number anywhere.
- No micron rating: so no microplastics or microbe claim can be checked against a pore size.
- Fits one product family: the mount you own or nothing, which is the trade a proprietary cartridge makes with you.
PUR Replacement Filter Cost Per Cartridge
A replacement cartridge is bought by the pack but billed by the gallon, and this is where a small tank turns into a real number. The cartridge is the cheapest object on any faucet mount page and the only one you buy again 4 times a year. The arithmetic across the aisle lives in our replacement cartridge comparisons.
- The pack: a $25 to $30 band at our last check for two cartridges, which is about $12 to $15 each. No single figure appears on this page.
- The gallon price: $12 to $15 divided by the rated 100 gallons is about 13 to 15 cents. The two pack therefore covers about 200 gallons for $25 to $30.
- The annual reality: at a gallon daily the 3 month clock fires four times, so a household spends about $50 to $60 a year on cartridges for a mount it bought once for about $33.
- The narrower comparison: the FC-01 cartridge runs about 4 cents a gallon at 320 gallons a cartridge, which is roughly a quarter of this figure and about $48 a year on the same drinking habit.
- The nine cent question: 13 to 15 cents against 4 cents is a 9 to 11 cent gap, which is about $33 to $40 across a household year. That's the price of keeping the mount you already own.
- The larger pack: PUR sells a six pack, which at the single cartridge band would be about $72 to $90 for eighteen months. Buying in bulk changes the timing of the bill, not the cents.
Here is the part the price tag hides: the cartridge is not where this system spends its money for the first year, and it's where it spends everything afterwards. A mount plus one cartridge is about $45 to $51. Across three years that is about $150 to $180 on a device that cost $33. Nobody's listing shows a three year number, which is exactly why the arithmetic belongs on a page like this one.
Think of it this way
A two pack is about six months of water and about $28, which is a little under 40 cents a week. That is a cheap habit by any measure, and it is still three times the cents of the wider cartridge that fits the same tap. The pack is not expensive, it is just not the cheapest way to do the same job.
Two cartridges is the six month pack, and the band on it moves with the season.
PUR RF-9999 Replacement Filter vs the Field
Every row below is a replacement cartridge from our own index, with certifications and capacities from our records. Nothing here is a manufacturer comparison chart, and the figures are bands rather than live prices.
| Cartridge | Standards | Rated life | Pack band |
|---|---|---|---|
| PUR RF-9999, 2 pack | NSF 42, 53, 401 | 100 gal each | $25 to $30 |
| Waterdrop FC-01 cartridge | NSF certified | 320 gal | $11 to $14 |
| Brita Elite faucet cartridge, 3 pack | NSF 42, 53 | 100 gal each | $40 to $47 |
| PUR pitcher filter, 3 pack | NSF 42, 53 | not recorded | $26 to $30 |
| AQUA CREST pitcher cartridge, 6 pack | NSF certified | not recorded | $15 to $19 |
Two things stand out. First, the table has two rows with no rated life in our records, which is not an accident of this page: the cheapest looking pitcher cartridges in the aisle are often the ones whose rated life nobody has written down. That's why they can't be scored per gallon here.
Second, the aftermarket copies deserve a mention. Waterdrop sells a cartridge under the same RF-9999 part number, and NSF's directory lists it at 300 gallons under standard 42 alone, with no 53 and no 401. Three times the tank, two fewer standards, and the listing's own warning about off brand filters is aimed at exactly that kind of part.
You're choosing between three certified standards on a small tank and one standard on a large one. The gallons favor the copy; the listing favors the original.
If the mount's cartridge cost is the problem, the same brand sells a pitcher route with a 53 certificate on it.
PUR Replacement Filter FAQ
- How long does a PUR RF-9999 filter last?
- 100 gallons or 3 months, whichever arrives first. At a gallon daily the calendar arrives at about 91 gallons, so a two pack covers roughly six months and a household buys 4 cartridges a year. The housing light counts it down, and a three second press resets it after a change.
- Is the RF-9999 the same as the RF-3375?
- They're two cartridge models in one performance data sheet: the sheet is written for replacement filter models RF3375 and RF9999, and both fit the faucet mount models listed alongside them. The listing sells the RF-9999 as the PUR PLUS filter and the RF-3375 as the standard one. Check the model you already have before ordering a pack, because the sheet covers both and the boxes look alike.
- Does it remove lead?
- Standard 53 is on the sheet with a printed reduction table, and lead is the contaminant that standard is most often bought for. The complication is the certification story: the sheet says the systems have been tested according to the standard, the storefront says the filters are certified by NSF and WQA as of 5/27/21, and the listing names IAPMO. Three surfaces, three answers, and no certification number on any of them.
- Can I use a cheaper aftermarket cartridge?
- You can, and the listing itself raises the issue: off brand filters may fit but aren't certified to work with the system. Waterdrop's copy of this part is NSF listed at 300 gallons under standard 42 alone, so it wins on gallons and loses on the health and trace compound standards. Fit is mechanical; certification is not.
- How often do I really need to change it?
- PUR says every three months for best performance, which at a gallon daily means you spend about 91 of the 100 gallons. A household drinking half a gallon a day spends closer to 45 gallons of the rating and still buys four cartridges a year. The clock is the schedule, not the tank, and the light is the clock.
PUR RF-9999 Replacement Filter: Where It Lands, the Best Paperwork on the Smallest Tank
The PUR RF-9999 Replacement Filter earns 3/7, and it is the clearest case in the batch of paperwork outrunning economics. It is the only replacement cartridge in our records whose data sheet names it by model and prints a reduction table against NSF/ANSI 42, 53, 401, it publishes its flow rate and pressure window, and it swaps in about twenty seconds without a tool.
It also holds 100 gallons a cartridge, runs about 13 to 15 cents a gallon, asks for 4 cartridges a year, and comes from a manufacturer that describes its certification three different ways across three surfaces without printing a number once.
If you own a PUR mount, this is the part that keeps it running and there's no decision to make. If you are still choosing the mount, the cartridge is the reason to look at the wider tank one aisle over: same two dollar coin, three times the gallons.
Three standards, a hundred gallons, four cartridges a year, and a certification story that changes with the page you read.
Where It Lands: Certified to Three Standards, Sized for One Season
Lead, mercury and the trace compounds covered by a printed reduction table, a twenty second swap, and a hundred gallon tank that a three month clock retires first. The paperwork is the best in the aisle; the gallons are the fewest.
PUR Replacement Filter Lexicon: Every Standard in This Review
- NSF/ANSI 42
- The aesthetic effects standard: chlorine, taste and odor. It is the standard every faucet cartridge in this aisle holds, and the one the aftermarket copies stop at.
- NSF/ANSI 53
- The health effects standard, covering lead, mercury, VOCs and more, certified per listing. On this cartridge it is the difference between a taste filter and a health filter.
- NSF/ANSI 401
- The emerging compounds standard, covering pharmaceuticals, flame retardants and other trace contaminants. A third standard on a faucet cartridge is unusual, and it is the strongest claim this part makes.
- Replacement filter model number
- The identifier for the cartridge itself, separate from the mount it fits. Here it is RF9999, written into the data sheet beside RF3375. A cartridge with a model number in the documentation is easier to buy correctly than one identified only by the device it feeds.
- Rated capacity
- The gallons a cartridge is certified to filter before performance is no longer covered. This one is 100, and the pack is twice that.
- Rated service flow
- The flow rate the system is rated at, in gallons per minute. 0.52 gpm here, about 67 ounces a minute, which is slower than the tap it hangs on and normal for carbon chemistry.
- Microbes
- Bacteria, viruses and cysts. PUR does not filter them, per the sheet's own footnote. Carbon and ion exchange are chemistry, and disinfection is a separate product class.
- Micron rating
- The pore size a filter captures, in micrometers. This cartridge does not publish one, which is why no microplastics claim appears on this page even though the brand's marketing makes one.
- Aftermarket cartridge
- A third party part built to fit a brand's housing, like the Waterdrop copy of this cartridge number. Fitting is a molding question; certification is an independent question with its own answer.
Keep Reading: More PUR Replacement Filter Reviews
- Best Replacement Filter Cartridges: the parent roundup, every cartridge in the index ranked by the running cost and rated life.
- PUR Water Filters Review: the whole PUR lineup, pitchers, dispensers and faucet systems, spec by spec.
- Best Faucet Mount Water Filters: the mounts this cartridge fits, and the ones that take a longer tank.
- The Nerd Stamp Methodology: how the 1 to 7 rating is calculated.