iSpring WGB31B vs iSpring WGB21B
Two of the whole-house water filters in our best whole-house water filters comparison, lined up spec by spec. Every figure comes from the manufacturer pages linked below, and the scores use the same published formula as the full ranking.
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Best for: 3-stage 10-inch whole-house sediment and carbon-block filter listed at 15 GPM
Check price at AmazonBest for: 2-stage 10-inch whole-house sediment and CTO filter listed at 15 GPM
Check price at AmazonSpec-by-spec comparison
Green marks the better published figure. "Not listed" means the manufacturer doesn't publish it.
| Spec | iSpring WGB31B | iSpring WGB21B | Weight |
|---|---|---|---|
| Filtration stagesStage count the maker lists for the system housing. Missing values take the category minimum. | 3 | 2 | 22% |
| Service or listed flowSystem flow the official page publishes in gallons per minute. Service flow is preferred and labelled; a single listed GPM is scored and labelled. Media rates in gpm/cu. ft. are not scored. Missing values take the category minimum. | 15 GPM | 15 GPM | 30% |
| Micron ratingFinest micron rating the official page publishes. Lower is a tighter filter. Missing values take the category minimum. | Not listed | Not listed | 16% |
| NSF/ANSI 42 or 53 namedYes when the official page names NSF/ANSI 42 or 53. NSF/ANSI 372 or 61 alone counts as no. | No | No | 20% |
| WarrantyLimited warranty length the official page publishes, in years. Missing values take the category minimum. | 1 yr | 1 yr | 12% |
| Stages (maker) | 3 stages (official product name) | 2 stages (official product name) | info |
| Flow rate (maker) | 15 GPM (official collection listing) | 15 GPM (official collection listing) | info |
| Micron rating (maker) | Not listed | Not listed | info |
| NSF/ANSI 42 or 53 (maker) | Not listed | Not listed | info |
| Warranty (maker) | 1-year manufacturer warranty (official page) | 1-year manufacturer warranty (official page) | info |
| Filter size (maker) | Not listed | 10" x 4.5" | info |
| HydroPick score | 2.7/10 | 2.2/10 | 100% |
Where each one comes out ahead
iSpring WGB31B
Better published figure on: Filtration stages.
What we like
Watch out for
- Micron rating not published by iSpring
iSpring WGB21B
No scored spec where it is strictly ahead; its case rests on the strengths below.
What we like
Watch out for
- Micron rating not published by iSpring
Verdict
Two 10-inch iSpring whole-house systems listed at 15 GPM with official 1-year warranties. The WGB21B is 2-stage; the WGB31B is 3-stage.
- iSpring WGB31B: iSpring: WGB31B
- iSpring WGB21B: iSpring: WGB21B