Six gravity water filters compared by what NSF, IAPMO and WQA certify each to reduce, with cost per gallon at certified capacity and a CDC safety note for untreated water. Prices checked October 2026.
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Our Choice for Best Gravity Filter
ProOne Big+
- Certified for lead, PFAS and microplastics (IAPMO)
- No power or plumbing
The short answer: The best gravity water filter for most homes is the ProOne Big+ (~$184). IAPMO certifies it to reduce lead, PFAS ("forever chemicals"), microplastics and chlorine, with no power or plumbing. For the broadest set of certified health claims in our certifier search, choose the Patriot Pure Ultimate (~$249), which NSF certifies for lead, arsenic (V), PFOA/PFOS and several other metals. To reduce fluoride, choose the Culligan ZeroWater 40-cup dispenser (~$72 to $90); ZeroWater's filter is the only gravity filter we know of with a certified fluoride claim. No gravity filter in our certifier search is certified to make untreated stream, pond or well water safe; see our safety note below.
Before you buy: A gravity filter is a countertop unit that lets water drip through filter elements from an upper chamber to a lower one, with no power or plumbing. That makes it slow but reliable in an outage. Check what is in your water first: city systems publish an annual report (EPA), and a private well needs a lab test.
| Filter | Best for | Certifier | Certified gallons per filter | Price | Filter cost per 100 gal | Check price |
|---|---|---|---|---|---|---|
| ProOne Big+ | Best overall | IAPMO | 50 | ~$184 | ~$126 | Amazon |
| Patriot Pure Ultimate | Broadest certified health claims | NSF | 200 | ~$249 | ~$50 | 4Patriots |
| Culligan MaxClear | Lead, PFAS and microplastics | IAPMO | 50 | ~$175 to $199 | ~$138 | Culligan |
| Culligan ZeroWater 40-cup | Budget pick; fluoride | IAPMO | 20 | ~$72 to $90 | ~$92 | Amazon |
| Waterdrop King Tank | Long maker-rated filter life, city water | IAPMO (materials only) | None certified | ~$240 | ~$1.32 (carbon filters only; maker rating) | Amazon |
| British Berkefeld Ultra Sterasyl | Certified cyst reduction | NSF | Not rated | ~$181 | Not rated | Doulton |
Prices were checked on each seller's site on October 4, 2026, and change often. Filter cost uses the per-filter price and the certified gallons per filter (ZeroWater from the $36.99 2-pack; Waterdrop from the maker's rating for its carbon pair).
What Each Filter Is Certified to Reduce
A ✓ means the contaminant appears on the product's certification listing. "Claim" means the maker says so, but no certifier lists it. "No" means no certifier lists it.
| Filter | Lead | PFAS | Fluoride | Cysts | Microplastics | Chlorine |
|---|---|---|---|---|---|---|
| ProOne Big+ | ✓ | ✓ Total PFAS | No | No | ✓ | ✓ |
| Patriot Pure Ultimate | ✓ | ✓ PFOA/PFOS | No | No | Claim | ✓ |
| Culligan MaxClear | ✓ | ✓ Total PFAS | No | No | ✓ | ✓ |
| Culligan ZeroWater 40-cup | ✓ | ✓ Total PFAS | ✓ | No | No | ✓ |
| Waterdrop King Tank | No | No | Claim | No | No | Claim |
| British Berkefeld Ultra Sterasyl | Claim | Claim | No | ✓ | ✓ | Claim |
Sources, checked October 4, 2026. ProOne: IAPMO 42, IAPMO 53, IAPMO 401. Patriot Pure: NSF. MaxClear: IAPMO 42, IAPMO 53, IAPMO 401. ZeroWater: IAPMO 42, IAPMO 53. Waterdrop: IAPMO 372. British Berkefeld: NSF.
How We Chose These Gravity Filters
Our methodology weighs evidence we could check ourselves:
- Certified claims. We searched the live listings of the three main certifiers: NSF, IAPMO and WQA. We mark a claim as certified only if it appears on the product's own listing; maker claims are labeled as such.
- Certified capacity. We divided each replacement filter's price by the gallons its certification covers, not the maker's larger rating. Waterdrop has no certified capacity, so its figure uses the maker's rating and is labeled.
- Availability. We confirmed each pick was on sale on October 4, 2026, and we note any replacement filter that was out of stock that day (Waterdrop's fluoride pair).
These are research-based picks. We did not test them ourselves, and the page carries no lab scores of our own. We fact-checked every certification, price and link on this page on October 4, 2026. If you spot an error, please contact us. To learn who we are, read more about us.
Replacement filter cost per 100 gallons, using each filter's certified capacity and per-filter price, October 4, 2026. Waterdrop's figure uses its own uncertified rating for the carbon filters only.
Certified capacity changes the math. ProOne's G3.0 element is certified for 50 gallons (IAPMO). Patriot Pure's Nanomesh filter is certified for 200 gallons (NSF). Waterdrop rates its carbon filters for 6,000 gallons, but no certifier lists that number.
Safety Note: Untreated Water
No gravity filter on this page is certified to make untreated water safe. NSF P231 is the protocol for microbiological water purifiers, and no gravity filter appears on its listing (NSF). For stream, pond, flood or untested well water, CDC says boiling is the best way to kill germs: bring it to a rolling boil for 1 minute (3 minutes above 6,500 feet). The next best option is to filter the water and then disinfect it (CDC). CDC says boiling, or filtering and then disinfecting, cannot make water safe if it is contaminated with chemicals, toxins or radioactive materials; use another source (CDC). The certified claims on this page apply to treated water of known quality. Use these filters on treated tap water, or on water you have already boiled.
The 6 Best Gravity Water Filters
1. ProOne Big+: Best Overall
The ProOne Big+ is a stainless steel gravity filter that uses ProOne's G3.0 elements. IAPMO certifies it to NSF/ANSI 42 for chlorine and chloramine, NSF/ANSI 53 for lead and Total PFAS, and NSF/ANSI 401 for microplastics (IAPMO 401 listing). We rank it first because ProOne's G3.0 systems and Culligan MaxClear are the only two gravity filter lines in our certifier search certified for lead, Total PFAS and microplastics together. Of the two, ProOne costs less per certified gallon at single-filter prices: about $126 vs $138 per 100 gallons. MaxClear's 6-pack cuts its cost to about $105. ProOne has held those listings since October 2024, and the Big+ scales from one to three elements.
- Price: ~$184 with one 7-inch element; ~$232 with two
- Filters: $63.16 per element, certified for 50 gallons each; ProOne says up to 6 months
- Warranty: 5 years on the stainless steel, 1 year on the element
Pros: certified for lead, Total PFAS and microplastics; stainless steel; adds elements to raise capacity.
Cons: 50 certified gallons per element is small, so filters cost about $126 per 100 gallons; slow, like all gravity filters; not certified for germs or fluoride.
Is it for you? Choose it for certified lead and PFAS reduction on treated tap water, with no power or plumbing.
2. Patriot Pure Ultimate: Broadest Certified Health Claims
The Patriot Pure Ultimate from 4Patriots holds the broadest set of certified health claims of any gravity filter in our certifier search; its NSF VOC claim alone covers a list of 53 chemicals and chemical groups. NSF certifies it to NSF/ANSI 53 for lead, arsenic (V), cadmium, chromium, copper, mercury, selenium, PFOA, PFOS and VOCs (NSF listing). It also holds NSF/ANSI 42 for chlorine and NSF/ANSI 401 for 15 emerging compounds. NSF notes the arsenic claim applies only to water at or below the tested arsenic level and form.
- Price: ~$249
- Filters: Nanomesh filter $99, certified for 200 gallons; a 5-pack is $399
- Tank: 2.25 gallons, stainless steel; holds up to 5 filters
Pros: the widest certified metals list here; certified for PFOA/PFOS; the lowest certified filter cost per gallon on this page.
Cons: not certified for microplastics or fluoride; the arsenic claim has limits.
Is it for you? Choose it if your water test shows several metals, such as lead, arsenic (V) or chromium.
3. Culligan MaxClear: Lead, PFAS and Microplastics
Culligan MaxClear comes in two sizes: the 3-gallon Venture and the 2.25-gallon Scout. IAPMO certifies both to NSF/ANSI 42 for chlorine and chloramine, NSF/ANSI 53 for lead and Total PFAS, and NSF/ANSI 401 for microplastics plus seven pharmaceuticals and pesticides (IAPMO 53 listing). Culligan calls it the only gravity filter certified for microplastics, lead and Total PFAS. The ProOne Big+ holds the same three claims, so Culligan's claim matches our certifier search only in its longer form, which adds pharmaceuticals and pesticides.
- Price: Venture ~$199, Scout ~$175, each with one filter
- Filters: $69 each, certified for 50 gallons; Culligan says up to 6 months
Pros: certified for lead, Total PFAS and microplastics; a broader 401 list than the ProOne's; two tank sizes.
Cons: the highest certified filter cost per gallon on this page at the single-filter price (about $105 per 100 gallons in a 6-pack); not certified for germs or fluoride.
Is it for you? Choose it if you want a certified PFAS and microplastics filter from a large brand. Need the smaller size? See the Scout.
4. Culligan ZeroWater 40-Cup: Best Budget Pick and Fluoride
The Culligan ZeroWater 40-cup is a glass dispenser with a five-stage filter that relies on ion exchange. IAPMO certifies it to NSF/ANSI 53 for lead, Total PFAS, fluoride, chromium-6, cadmium, copper and mercury (IAPMO 53 listing). Its filter is the only gravity filter in our certifier search with a certified fluoride claim; Culligan's other ZeroWater pitchers and dispensers use the same filter and listing. Culligan says it removes nearly all dissolved solids.
- Price: ~$72 on Amazon; $89.99 at Culligan
- Filters: certified for 20 gallons each; a 2-pack is $36.99
- Extras: a TDS meter to tell you when the filter is spent
Pros: certified for fluoride, lead and Total PFAS; low upfront price; glass tank.
Cons: 20-gallon filters mean frequent changes; not certified for microplastics; has plastic parts despite the glass tank.
Is it for you? Choose it if fluoride is your main concern, or if you want certified lead and PFAS reduction for under $100. See our best fluoride water filters.
5. Waterdrop King Tank: Long Filter Life for City Water
The Waterdrop King Tank is a 2.25-gallon stainless steel gravity filter with carbon and fluoride filters. Its only certification is NSF/ANSI 372 for lead-free materials (IAPMO listing). Waterdrop says it reduces chlorine and fluoride, but no certifier lists those claims. Waterdrop also says its fluoride filters begin to lose effectiveness after a few hundred gallons.
- Price: ~$240 on Amazon with the stand and fluoride filters (November 2026)
- Filters: carbon pair rated for 6,000 gallons ($78.99); fluoride pair rated for 1,000 gallons ($56.99, out of stock on October 4, 2026)
- Setup: the carbon filters need priming before first use
Pros: very long maker-rated filter life; low running cost; stainless steel.
Cons: no reduction certification; fluoride refills were out of stock; priming takes time.
Is it for you? Choose it for chlorine taste on city water if you accept maker claims in exchange for very low running costs.
6. British Berkefeld Ultra Sterasyl: Certified Cyst Reduction
A ceramic element is a porous ceramic filter with tiny pores that trap particles and cysts. The British Berkefeld gravity system from Doulton uses Ultra Sterasyl ceramic elements. NSF certifies it to NSF/ANSI 53 for cyst and turbidity reduction, and to NSF/ANSI 401 for microplastics (NSF listing). It and its Ultra Fluoride sibling are the only gravity tank systems in our certifier search with a certified cyst claim. It is not certified for lead, PFAS or chlorine, and cyst reduction is not the same as disinfection.
- Price: ~$181 for the 8.5-liter size with two elements; 6- and 12-liter sizes are also sold; check that your size is on the NSF listing
- Filters: $23.95 per element; NSF notes that capacity claims do not apply to mechanical filtration
Pros: certified for cysts and microplastics; low element price; stainless steel.
Cons: not certified for lead, PFAS or chlorine; still needs disinfection for untreated water.
Is it for you? Choose it as a cyst barrier for treated water, or pair it with boiling or disinfection.
NSF, IAPMO and WQA Certified Gravity Filters
Looking for an NSF-certified or WQA-certified gravity water filter? This table covers the gravity units we reviewed or checked for this guide, as listed by each certifier on October 4, 2026, and what each listing covers. It is not a full list. Brita and PUR also hold certifier listings for many more pitchers and dispensers, and their claims vary by filter, so check the listing for your model.
| Certifier | Gravity units listed | What the listing covers |
|---|---|---|
| NSF | Patriot Pure Ultimate | Chlorine (42); lead, arsenic (V), PFOA/PFOS, other metals and VOCs (53); 15 emerging compounds (401) |
| NSF | British Berkefeld SS2 (Ultra Sterasyl, Ultra Fluoride) | Particulates (42); cysts and turbidity (53); microplastics (401) |
| NSF | Phoenix Gravity; Berkey with Phoenix elements | Chlorine taste and odor only (42) |
| IAPMO | ProOne Big+ and Traveler+ (G3.0); Culligan MaxClear Venture and Scout | Chlorine, chloramine (42); lead, Total PFAS (53); microplastics, plus seven pharmaceuticals and pesticides for MaxClear (401) |
| IAPMO | Culligan ZeroWater pitchers and dispensers (one shared filter) | Chlorine (42); lead, Total PFAS, fluoride, chromium-6, cadmium, copper and mercury (53); 13 emerging compounds (401) |
| WQA | Boroux Legacy | Particulates only (42); microplastics (401) |
| WQA | Brita UltraMax dispenser; PUR dispensers (plastic) | Chlorine, taste and odor (42); lead, mercury, cadmium, copper and some VOCs and pesticides, plus asbestos for Brita, by filter (53); microplastics (401) |
| WQA | LifeStraw Home 7-cup glass pitcher | Chlorine, particulates, taste and odor (42); lead, mercury, cadmium, copper and cysts (53); microplastics (401) |
| NSF and WQA | Clearly Filtered pitcher | Chlorine taste and odor only (42) |
NSF/ANSI 53 is the standard for health claims, such as lead and PFAS. NSF/ANSI 42 covers taste and odor, and NSF/ANSI 401 covers emerging compounds such as pharmaceuticals (NSF); microplastics claims also fall under 401. PFAS claims now sit under NSF/ANSI 53; NSF retired its older P473 protocol (NSF). Certified capacity is the number of gallons the certifier tested a filter for. Replace the filter at that point, even if water still flows.
Also Considered
- Alexapure Pro (~$280): no NSF, IAPMO or WQA listing. Its maker publishes lab tests, and it says to follow boil-water or disinfection guidance for water that may be unsafe. It is not sold in California.
- Epic Pure XP dispenser (~$99): NSF lists its filter for material safety only; its reduction figures are lab tests the maker reports. See the Epic Pure.
- Clearly Filtered pitcher: certified only for chlorine taste and odor; see our activated carbon filter guide.
- Boroux Legacy (~$355 to $399): WQA lists it for particulates and microplastics only, not lead or PFAS.
- Berkey: no certifier lists the Black Berkey elements. EPA issued stop-sale orders in 2022 and 2023. On September 18, 2026, a federal appeals court upheld a lower court's refusal to temporarily block the 2023 order; the underlying case can continue (First Circuit). See our Big Berkey review.
Frequently Asked Questions
Are Culligan gravity filters good?
Yes, on certification. IAPMO certifies Culligan MaxClear for lead, Total PFAS and microplastics, and the Culligan ZeroWater dispenser for lead, Total PFAS and fluoride. The trade-off is small certified filter capacities: 50 gallons for MaxClear and 20 for ZeroWater.
What are the disadvantages of gravity filters?
They are slow, and many have small certified filter capacities, so filters can be costly per gallon. None on this page is certified to make untreated water safe. They also take up counter space and need manual refilling.
Do gravity filters remove fluoride?
Most are not certified to. The Culligan ZeroWater 40-cup dispenser is certified for fluoride under NSF/ANSI 53. Waterdrop claims fluoride reduction for the King Tank, but no certifier lists it.
Do gravity filters remove bacteria and viruses?
None on this page is certified to. CDC says to boil untreated water, or filter it and then disinfect it. Most portable filters remove parasites but not viruses or bacteria, according to CDC. The British Berkefeld is certified for cysts, which are parasites, but that is not disinfection.
Which gravity filter removes heavy metals?
The Patriot Pure Ultimate is certified for lead, arsenic (V), cadmium, chromium, copper, mercury and selenium. The Culligan ZeroWater is certified for lead, chromium-6, cadmium, copper and mercury. Check that your metal appears on the listing.
How long do gravity filters last?
Go by certified gallons: 20 for ZeroWater, 50 per element for ProOne and MaxClear, and 200 for Patriot Pure. Divide by the gallons you use each day to estimate the days between changes. Makers often quote longer lives in months, but the certified gallons are what the certifier tested.
Key Takeaways
- Best overall: ProOne Big+ (~$184), IAPMO-certified for lead, Total PFAS and microplastics.
- Broadest certified health claims: Patriot Pure Ultimate (~$249), NSF-certified for lead, arsenic (V) and PFOA/PFOS.
- For fluoride: Culligan ZeroWater 40-cup (~$72 to $90), certified for fluoride.
- Check certified gallons, not the maker's rating, when you compare filter costs.
- No gravity filter here is certified to make untreated water safe. Boil it, or filter and then disinfect it (CDC).
Comparing other filter types? See our guides to the best activated carbon water filters, UV water purifiers, water filters for microplastics and how to purify water for drinking.
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