Water · Gear Review
The ProOne Big+ is our top pick for most households. Here is how it compares to five alternatives, what the Berkey situation actually means, and which certifications to trust.
The verdict
Before the full comparison: here is where we land and why.
Best overall
IAPMO-certified to NSF/ANSI 42, 53, 372, and 401. The G3.0 filter is the only gravity filter element independently certified to remove total PFAS, lead, and microplastics simultaneously. No priming required. Filter life up to 9 months per element. At $280–$300 with two filters included, it is the strongest independently verified system in this category.
$280–$300 · Amazon Associates tag applies
Best for PFAS focus
IAPMO-certified to NSF/ANSI 53 for 99.7% total PFAS reduction, plus lead and microplastics. The mainstream brand backing and retail availability make this the easiest recommendation for households that are primarily concerned about forever chemicals. Higher ongoing filter cost is the tradeoff.
$200–$250 system · ~$90–$100/filter · Amazon Associates tag applies
Best flow rate
4 GPH, stainless steel, no priming. Certified NSF 42 and 372. Third-party lab data shows lead and contaminant reduction but no NSF 53 PFAS certification. Best choice when daily volume and flow rate matter most.
~$200–$250
Trusted long-track-record
Hybrid ceramic gravity block. Independent lab testing shows bacteria and virus removal. Widely trusted in the preparedness community. Less published certification data than ProOne but solid real-world track record.
~$250–$280
Strongest ceramic pedigree
Doulton-manufactured Ultra Sterasyl ceramic candles. The longest-running independently certified gravity filter brand. Strong microbiological removal data. Best for households that want ceramic candle technology with deep independent test history.
~$300–$320
Budget, apartment, or pitcher use
A different format: pitcher-style, not stainless countertop. NSF-certified for PFAS, lead, and hundreds of contaminants. Lower upfront cost, smaller footprint. Best for renters, apartments, or supplemental filtration alongside other systems.
~$90
Affiliate disclosure: New World Survival earns a small commission on purchases made through links on this page, at no cost to you. This helps us cover operating costs and keep building new content. We only recommend gear we would put in our own kit.
The Berkey situation
If you own a Berkey or were considering one, here is the plain-language version of where things stand.
What happened
In late 2022 and 2023, the EPA issued Stop Sale, Use or Removal Orders (SSUROs) against Berkey's US distributors. The agency classified Black Berkey filter elements as unregistered pesticide devices under FIFRA because they contain silver, which functions as an antimicrobial agent. Manufacturer New Millennium Concepts filed suit challenging the classification. The district court dismissed the case in 2024 on jurisdictional grounds; the appeal is now before the Fifth Circuit. The case is pending with no trial date set as of mid-2026.
What is available now
Berkey stainless steel housing systems remain available for purchase. New systems ship with Black Berkey elements included. Standalone Black Berkey replacement elements are sold out at all authorized dealers — production is halted by the stop-sale order and pre-existing inventory is depleted. Phoenix replacement elements are the current endorsed option. Phoenix elements carry NSF/ANSI 42 and 372 certifications, which is a narrower certification scope than the original Black Berkey elements claimed.
What it means if you already own a Berkey
Your housing is fine. If your current Black Berkey elements are functioning, continue using them. When replacement is needed, Phoenix elements are the current option from authorized dealers. They filter chlorine, taste, and odor at a certified level, but their certification scope for contaminants like PFAS and microbiological removal is not as extensively documented as the original elements were claimed to be. ProOne G3.0 elements are also compatible with Berkey housings and carry stronger independent certifications.
What it means for new buyers
Given the unresolved regulatory situation and the uncertainty around ongoing element availability, we recommend against purchasing a Berkey system as a primary household filter at this time. The alternatives reviewed here offer comparable or superior independent certification with more predictable supply chains. If the lawsuit resolves in Berkey's favor and standalone elements return to market with documentation, that calculus may change.
Disclosure
Berkey products are referenced in this review for context. NWS does not currently recommend Berkey as a primary household filter due to the ongoing EPA stop-sale order affecting Black Berkey replacement elements. The legal situation is active and may change. This review will be updated if material changes occur.
How we evaluated
The gravity filter market has a history of large performance claims without independent verification. This review evaluates what is certified, not what is claimed.
Certifications issued by NSF International, IAPMO R&T, or WQA against NSF/ANSI standards. Self-reported manufacturer testing and third-party lab data are noted but weighted lower. The specific standards matter: NSF 42 covers taste and odor; NSF 53 covers health effects including PFAS and lead; NSF 372 covers lead-free construction; NSF 401 covers emerging contaminants.
Weight: highest
What the filter verifiably removes: chlorine, lead, PFAS, heavy metals, bacteria, protozoa. The household preparedness context weights PFAS and microbiological removal most heavily, as these represent the two growing categories of water quality concern in North American municipal supply.
Weight: high
A system's total cost over 5 years matters more than purchase price. Filter replacement intervals, element cost, and rated gallons per element determine the real cost of ownership. Wide variation exists in this category: from under $0.10/gallon to over $1.00/gallon.
Weight: high
Gallons per hour under normal gravity conditions. A system that filters slowly is not usable as a daily driver for a family of four. Flow rate degrades as elements load; the rate at 50% element life is more relevant than the rated maximum.
Weight: medium
The Berkey situation illustrated that a great filter is only as good as its ongoing element supply. Replacement element availability, manufacturer stability, and compatibility with other filter elements are evaluated here. Systems where elements fit multiple housings have an advantage.
Weight: medium-high
Material quality (stainless steel grade, spigot type), priming requirements, ease of maintenance, and whether the system requires electricity or plumbing. For preparedness use, no-electricity operation and simple setup are baseline requirements.
Weight: medium
The picks
Best overall — strongest certified performance
The ProOne Big+ earns the top position because no other system in this comparison combines independent certification breadth with practical filter performance at this price. The G3.0 filter elements carry IAPMO certification against NSF/ANSI 42, 53, 372, and 401 — making them the only gravity filter elements with independent certification covering total PFAS, lead, microplastics, and chlorine simultaneously.
The no-priming design is meaningful for preparedness use. Gravity filters typically require the elements to be saturated with clean water before first use. ProOne's elements work immediately with source water, including raw water from natural potable sources. Each 7-inch element is rated to approximately 1,500 gallons. Two elements, which ship with the Big+, give a combined capacity of around 3,000 gallons before replacement, at a filter cost of roughly $160–$180.
The housing is 304 polished stainless steel, 9 inches in diameter, 22.75 inches tall with the stand. Capacity is approximately 2.25 gallons in each chamber. The ProOne G3.0 elements also fit most competitor housings, including Berkey, Alexapure, and Waterdrop, which provides flexibility if you already own a different housing.
At a glance
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Best for PFAS — the certified mainstream option
Culligan entered gravity filtration in 2026 with a system built around MaxClear ceramic filter technology, manufactured on the ProOne platform. The IAPMO certification to NSF/ANSI 53 covers 99.7% total PFAS reduction — the highest independently verified PFAS claim in the gravity filter category — along with lead and microplastics.
The Culligan name brings mainstream retail presence and customer support infrastructure. For households that are specifically purchasing a gravity filter due to PFAS concerns in their municipal supply, the MaxClear provides the clearest independently certified path to documented PFAS reduction without requiring reverse osmosis or an under-sink system.
The meaningful limitation is ongoing filter cost. Replacement filters run approximately $90–$100 each, with a recommended replacement interval of every six months. That translates to $180–$200 per year in filter costs alone — the highest ongoing cost in this comparison. Households filtering high volumes will feel this more than those using the system primarily for drinking water.
At a glance
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Best flow rate — for daily household volume
The Waterdrop King Tank's standout attribute is flow rate. At 4 gallons per hour, it filters water roughly twice as fast as most gravity filter competitors, making it practical as a daily drinking water source for a household of four. The 304 stainless steel construction and integrated metal water-level indicator are well-made for the price.
The certification picture requires transparency. Waterdrop carries NSF/ANSI 42 (chlorine, taste, odor) and 372 (lead-free construction). Third-party lab testing published by Waterdrop and independent reviewers shows lead, fluoride, and heavy metal reduction. However, there is no NSF/ANSI 53 PFAS certification as of mid-2026. For households primarily concerned about chlorine taste and general water quality, the King Tank is a sound choice. For households specifically seeking documented PFAS protection, the ProOne or Culligan MaxClear provide that certification.
The black carbon filters are rated to 6,000 gallons per pair, delivering among the better cost-per-gallon figures in this category at scale.
At a glance
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Trusted preparedness pick — established track record
The Alexapure Pro has a long standing among households focused on preparedness, and for good reason. The hybrid ceramic gravity block filter removes bacteria and viruses per independent lab data, placing it among the few gravity filters with documented microbiological removal at the household scale. The system has proven reliable in the preparedness community over several years of real use.
The certification picture is less complete than ProOne. Alexapure has published independent lab testing results covering a range of contaminants, but the formal NSF/ANSI certification structure is less extensive. PFAS certification is not published. For households that value microbiological protection and a track record in emergency preparedness, the Alexapure remains a sound choice at a competitive price.
The single-filter element design, rated to 5,000 gallons, keeps ongoing costs manageable at approximately $50 per replacement filter per year of normal use.
At a glance
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Best ceramic pedigree — deepest independent test history
British Berkefeld is the oldest independently certified gravity filter system in this comparison, manufactured by Doulton using Ultra Sterasyl ceramic candle elements. Doulton has been producing certified ceramic water filters since the Victorian era; the current elements carry strong third-party certifications for microbiological removal including bacteria, protozoa, and cysts.
The 3.17-gallon stainless steel system is larger than most competitors. The ceramic candle design requires periodic cleaning rather than replacement at fixed intervals, which appeals to households that prefer maintenance-over-replacement economics. The candles are inspected visually for integrity before each use.
The tradeoff is that British Berkefeld, like Alexapure, does not publish NSF/ANSI 53 PFAS certification. The system excels at microbiological protection and has an unmatched track record in that area. Households that prioritize PFAS removal should pair it with point-of-use testing or consider a system with PFAS certification.
At a glance
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Budget, apartment, or supplemental use — different format
The Clearly Filtered Pitcher is a different category of product from the five stainless steel countertop systems above. It is a pitcher-format filter, not a large countertop unit, and it belongs in this review because it is often compared against gravity filter systems by readers deciding how much to invest in home filtration.
The certification case for Clearly Filtered is strong. The pitcher is NSF-certified for removal of over 360 contaminants, including PFAS, lead, chlorine, and microplastics. For households in apartments, renters, or anyone whose living situation makes a countertop gravity filter impractical, the Clearly Filtered Pitcher provides certified PFAS protection at roughly one-third the system cost.
The practical differences: capacity is smaller (around 80 oz), flow rate through the filter is slow, and the unit requires refrigerator storage to keep filtered water cold and fresh. For dedicated preparedness use, the stainless countertop systems above are more appropriate. For daily drinking water filtration with certified performance at lower cost, the Clearly Filtered Pitcher is a serious option.
At a glance
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What we didn't pick and why
The underlying technology is sound and the brand has a long loyal following. The reason we don't recommend new Berkey purchases as a primary system is supply chain uncertainty. Standalone Black Berkey elements are sold out. Phoenix replacement elements carry narrower certifications. The Fifth Circuit case has no scheduled resolution date. Until the element supply situation stabilizes and the certification picture for replacement elements is clearer, the alternatives reviewed here provide better value certainty.
If you already own a Berkey housing, ProOne G3.0 elements are compatible and carry stronger independent certifications.
ZeroWater pitchers reduce TDS (total dissolved solids) to near-zero using a five-stage ion exchange process. The TDS reading is a popular talking point. The problem is that ion exchange strips minerals beneficial to health alongside harmful contaminants, and some research suggests very-low-TDS water may have implications for mineral absorption. More practically, ZeroWater filters clog faster than competitors with hard water, and replacement frequency and cost add up. The Clearly Filtered Pitcher provides certified contaminant removal with a more reasonable filter lifespan.
TDS is not a certification standard for drinking water safety.
Amazon carries dozens of stainless gravity filter systems, many at $60–$120, that visually resemble the ProOne, Alexapure, and Berkey. Several come with certification claims. The problem is traceability: the certification documents, when they exist, are often for filter elements purchased from a third-party supplier and tested to NSF 42 only, not NSF 53. Before purchasing any gravity filter not on this list, verify the certification issuer (NSF International, IAPMO, or WQA), the specific NSF standards covered, and whether the element in the current product matches the tested element.
NSF 42 alone covers taste and odor — it does not cover health contaminants.
Buying guide
Question 1
If your water utility has detected PFAS or you are in a known PFAS-affected area, certified PFAS removal is the primary criterion. ProOne Big+ (NSF 53 certified for total PFAS) and Culligan MaxClear (IAPMO NSF 53, 99.7% PFAS) are the only systems in this comparison with that certification. Choose between them based on filter replacement cost: ProOne's elements last longer at lower per-year cost; Culligan MaxClear has a higher ongoing cost but stronger mainstream support infrastructure.
Question 2
For daily use as a household drinking water source, the Waterdrop King Tank's 4 GPH flow rate makes it most practical for a family of four filtering 3–5 gallons per day. For emergency backup that sits ready and sees occasional use, flow rate matters less and filter longevity matters more. The ProOne Big+ and Alexapure Pro are excellent emergency backup systems. A filter used only during emergencies will likely never need element replacement.
Question 3
System price is not the real number. Filter replacement cost over five years tells you what you are actually spending. Approximate 5-year total costs assuming 2 gallons per day household use:
What NSF certifications mean
Self-reported lab testing is not a certification. Look for certifications issued by NSF International, IAPMO R&T, or WQA. NSF 42 alone covers taste — it does not cover health contaminants. A filter certified to NSF 42 and NSF 53 (PFAS scope) is meaningfully different from one certified to NSF 42 only.
How this fits
The complete Water Ladder covers storage, treatment, collection, conservation, and resupply. A gravity filter is the treatment layer — see how it connects to the rest of a household water capability.
Explore the water domain →
The companion educational guide explains how gravity filters work, what certifications to look for, and how to size a system for your household. Covers the Berkey situation in depth.
Read the guide →
A gravity filter handles your stationary household needs. A portable filter — Sawyer Squeeze or LifeStraw Peak — covers filtration when you are away from home or moving water between locations.
See portable filter review →
Next steps
Starting out
The Household Water Audit shows how many gallons your household actually needs and where your biggest gaps are before you buy anything.
Take the water auditReady to go deeper
Before choosing a filter, know what is in your water. A lab test from Tap Score or SimpleLab tells you which certifications actually matter for your specific supply.
See the water testing guide