3M Aqua-Pure AP904
#6 in CartridgeFull review
The AP903 with scale inhibitor added, for city water that is both chlorinated and hard.
Amazon $421.18$421.18
The 3M Aqua-Pure AP904 is the better whole-house water filter overall, rated 3.1 to 2.2. The 3M Aqua-Pure AP904 leads on certification, warranty and price. The 3M Aqua-Pure AP904 costs $328.81 less ($421.18 vs $749.99).
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.
iSpring WGB32B-PFKS
#19 in CartridgeFull review
For city water with a PFAS notice, where a cartridge system beats a tank on upfront cost. Budget for the yearly PFAS cartridge.
Amazon $749.99$749.99
Which should you buy?
- Choose the 3M Aqua-Pure AP904 for certification (certified to NSF/ANSI 42 vs no certification in a public listing, no tested to claim), warranty (25-year warranty vs 1-year warranty) and price ($421.18 vs $749.99).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every cartridge whole-house water filter; a clear win is highlighted. How we rank explains each one.
| Factor weight | 3M Aqua-Pure AP904 | iSpring WGB32B-PFKS |
|---|---|---|
| Overall rating | 3.1/5 | 2.2/5 |
| Running cost 25% | 0 $3.47 per 1,000 gallons ($347.15 every 100,000 gallons) | 50 filter cost or capacity not published (neutral score used) |
| Certification 25% | 60 certified to NSF/ANSI 42 | 0 no certification in a public listing, no tested to claim |
| Flow 15% | 50 10 gpm service flow | 50 flow not published (neutral score used) |
| Price 20% | 38 $421.18 | 4 $749.99 |
| Warranty 15% | 100 25-year warranty | 0 1-year warranty |
Specifications
| 3M Aqua-Pure AP904 | iSpring WGB32B-PFKS | |
|---|---|---|
| Filtration | ||
| Capacity | 100,000 gallons | 100,000 gallons |
| Replacement filters or media | $347.15 | - |
| Running cost | $3.47 per 1,000 gal | - |
| Stages | 1 | 3 |
| Certified | NSF/ANSI 42 | - |
| Chloramine | No | Yes |
| PFAS | No | Yes |
| Build | ||
| Flow | 10 gpm | - |
| Ports | 1 in | 1 in |
| UV stage | No | No |
| Warranty | 25 years | 1 year |