A lower priced three stage big blue system for city water. Running cost is hard to judge without a gallon rating.
Amazon $254.99The Waterdrop WHF3T-PG and the 3M Aqua-Pure AP903 are evenly matched, rated 3.2 and 3.1. The Waterdrop WHF3T-PG leads on flow and price. The 3M Aqua-Pure AP903 wins on warranty and certification. The Waterdrop WHF3T-PG costs $168 less ($254.99 vs $422.99).
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.
A certified, low mess choice for city water with chlorine, for owners who would rather pay more per cartridge than handle filters.
Amazon $422.99Which should you buy?
- Choose the Waterdrop WHF3T-PG for flow (15 gpm service flow vs 10 gpm service flow) and price ($254.99 vs $422.99).
- Choose the 3M Aqua-Pure AP903 for warranty (25-year warranty vs 1-year warranty) and certification (certified to NSF/ANSI 42 vs tested to NSF/ANSI 42, not certified).
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 | Waterdrop WHF3T-PG | 3M Aqua-Pure AP903 |
|---|---|---|
| Overall rating | 3.2/5 | 3.1/5 |
| Running cost 25% | 50 filter cost or capacity not published (neutral score used) | 8 $2.45 per 1,000 gallons ($244.77 every 100,000 gallons) |
| Certification 25% | 30 tested to NSF/ANSI 42, not certified | 60 certified to NSF/ANSI 42 |
| Flow 15% | 100 15 gpm service flow | 50 10 gpm service flow |
| Price 20% | 68 $254.99 | 38 $422.99 |
| Warranty 15% | 0 1-year warranty | 100 25-year warranty |
Specifications
| Waterdrop WHF3T-PG | 3M Aqua-Pure AP903 | |
|---|---|---|
| Filtration | ||
| Capacity | 100,000 gallons | 100,000 gallons |
| Replacement filters or media | - | $244.77 |
| Running cost | - | $2.45 per 1,000 gal |
| Stages | 3 | 1 |
| Certified | - | NSF/ANSI 42 |
| Tested to (not certified) | NSF/ANSI 42 | - |
| Chloramine | No | No |
| PFAS | No | No |
| Build | ||
| Flow | 15 gpm | 10 gpm |
| Ports | 1 in | 1 in |
| UV stage | No | No |
| Warranty | 1 year | 25 years |
