ProOne Big+ 3 Gal
A 3 gal stainless gravity filter that uses ProOne G2.0 filters. A mid-priced option, though the listing publishes little about flow, filter gallons or warranty.
Amazon $229.95$229.95
The ProOne Big+ 3 Gal and the Boroux Legacy 3 Gal are evenly matched, rated 3.1 and 3.0. The ProOne Big+ 3 Gal leads on value and certification. The ProOne Big+ 3 Gal costs $169.05 less ($229.95 vs $399).
Prices were last checked November 9, 2026. Product prices and availability are accurate as of that date and are subject to change; the price and availability shown on Amazon or the retailer's site at the time of purchase apply. As an Amazon Associate we earn from qualifying purchases.
Boroux Legacy 3 Gal
A Royal Berkey sized 3 gal stainless filter with long-life carbon filters. A fair price, but the filters lack an NSF reduction certification.
Amazon $399$399
Which should you buy?
- Choose the ProOne Big+ 3 Gal for value ($76.65 per gallon of capacity ($229.95, 3 gal) vs $133 per gallon of capacity ($399, 3 gal)) and certification (states certification to NSF/ANSI 42 vs states certification to NSF/ANSI/CAN 372).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every 2.5 to 3.5 gal gravity water filter; a clear win is highlighted. How we rank explains each one.
| Factor weight | ProOne Big+ 3 Gal | Boroux Legacy 3 Gal |
|---|---|---|
| Overall rating | 3.1/5 | 3.0/5 |
| Value 25% | 73 $76.65 per gallon of capacity ($229.95, 3 gal) | 39 $133 per gallon of capacity ($399, 3 gal) |
| Running cost 15% | 50 replacement cost or element life not published (neutral score used) | 71 $0.013 per gallon filtered ($79.50 per element, 6,000 gal each) |
| Capacity 15% | 33 3 gal tank | 33 3 gal tank |
| Certification 20% | 30 states certification to NSF/ANSI 42 | 10 states certification to NSF/ANSI/CAN 372 |
| Element life 15% | 50 element life in gallons not published (neutral score used) | 100 6,000 gal rated per element |
| Warranty 10% | 0 warranty not published, scored as none | 0 warranty not published, scored as none |
Specifications
| ProOne Big+ 3 Gal | Boroux Legacy 3 Gal | |
|---|---|---|
| Capacity and flow | ||
| Tank capacity | 3 gal | 3 gal |
| Price per gallon of capacity | $76.65 | $133 |
| Elements included | - | 2 |
| Maximum elements | - | 4 |
| Filtration | ||
| Element type | ProOne G2.0 ceramic and carbon element, 7 in | Boroux Foundation Black carbon element, 9.5 in |
| Certified | NSF/ANSI 42 | NSF/ANSI/CAN 372 |
| Certification detail | Listing: G2.0 filters carry NSF/ANSI 42 certification and were tested by an independent lab to other NSF standards. The title also says IAPMO certified to reduce lead, total PFAS and microplastics. | Filter listing (maker copy): NSF/ANSI/CAN 372 certified by WQA, a lead-free materials standard, not a contaminant reduction certification. System listing: filters tested and independently verified by third-party accredited laboratories, none named. |
| Fluoride | - | Add-on filter |
| Running cost | ||
| Rated life per element | - | 6,000 gal each |
| Replacement element | - | 79.5 $ |
| Cost per gallon filtered | - | $0.013 |
| Build | ||
| Material | stainless steel | 304 stainless steel |
| Height | - | 23 in |
| Diameter | - | 9 in |
| Weight | - | 9.5 lb |