3M Aqua-Pure AP903
#4 in CartridgeFull review
A certified, low mess choice for city water with chlorine, for owners who would rather pay more per cartridge than handle filters.
Amazon $422.99$422.99
The 3M Aqua-Pure AP903 and the 3M Aqua-Pure AP904 are evenly matched, rated 3.1 and 3.1. The 3M Aqua-Pure AP904 costs $1.81 less ($421.18 vs $422.99).
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
Prices were last checked November 2, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
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 AP903 | 3M Aqua-Pure AP904 |
|---|---|---|
| Overall rating | 3.1/5 | 3.1/5 |
| Running cost 25% | 8 $2.45 per 1,000 gallons ($244.77 every 100,000 gallons) | 0 $3.47 per 1,000 gallons ($347.15 every 100,000 gallons) |
| Certification 25% | 60 certified to NSF/ANSI 42 | 60 certified to NSF/ANSI 42 |
| Flow 15% | 50 10 gpm service flow | 50 10 gpm service flow |
| Price 20% | 38 $422.99 | 38 $421.18 |
| Warranty 15% | 100 25-year warranty | 100 25-year warranty |
Specifications
| 3M Aqua-Pure AP903 | 3M Aqua-Pure AP904 | |
|---|---|---|
| Filtration | ||
| Capacity | 100,000 gallons | 100,000 gallons |
| Replacement filters or media | $244.77 | $347.15 |
| Running cost | $2.45 per 1,000 gal | $3.47 per 1,000 gal |
| Stages | 1 | 1 |
| Certified | NSF/ANSI 42 | NSF/ANSI 42 |
| Chloramine | No | No |
| PFAS | No | No |
| Build | ||
| Flow | 10 gpm | 10 gpm |
| Ports | 1 in | 1 in |
| UV stage | No | No |
| Warranty | 25 years | 25 years |