Express Water Ultimate Protection WH300SCKP
#15 in CartridgeFull review
The best value of Express Water’s three stage systems, for hard city water with old pipes. Its claims aren’t certified.
Amazon $443.14$443.14
The Express Water Ultimate Protection WH300SCKP is the better whole-house water filter overall, rated 2.4 to 2.4. The Express Water Ultimate Protection WH300SCKP costs $56.85 less ($443.14 vs $499.99).
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.
Express Water Heavy Metal WH300SCKS
#17 in CartridgeFull review
A frame mounted three stage system for city water where lead from old pipes is the worry. Its heavy metal claims aren’t certified.
Amazon $499.99$499.99
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 | Express Water Ultimate Protection WH300SCKP | Express Water Heavy Metal WH300SCKS |
|---|---|---|
| Overall rating | 2.4/5 | 2.4/5 |
| Running cost 25% | 19 $1.78 per 1,000 gallons ($177.64 every 100,000 gallons) | 15 $1.99 per 1,000 gallons ($198.88 every 100,000 gallons) |
| Certification 25% | 0 no certification in a public listing, no tested to claim | 0 no certification in a public listing, no tested to claim |
| Flow 15% | 100 15 gpm service flow | 100 15 gpm service flow |
| Price 20% | 35 $443.14 | 28 $499.99 |
| Warranty 15% | 0 1-year warranty | 0 1-year warranty |
Specifications
| Express Water Ultimate Protection WH300SCKP | Express Water Heavy Metal WH300SCKS | |
|---|---|---|
| Filtration | ||
| Capacity | 100,000 gallons | 100,000 gallons |
| Replacement filters or media | $177.64 | $198.88 |
| Running cost | $1.78 per 1,000 gal | $1.99 per 1,000 gal |
| Stages | 3 | 3 |
| Chloramine | No | No |
| PFAS | No | No |
| Build | ||
| Flow | 15 gpm | 15 gpm |
| Ports | 1 in | 1 in |
| UV stage | No | No |
| Warranty | 1 year | 1 year |