1 / 7iSpring US31 3-Stage Under-Sink Water Filter System
The iSpring US31 is a three-stage under-sink water filter system supplied with a dedicated faucet. Its listed filtration targets include chlorine, sediment, taste and odors, while the listing says it does not reduce TDS.
At a glance
- Three filtration stages use PP, GAC and CTO cartridges, according to the listing.
- The listed flow rate is 1 gpm for on-demand water at the dedicated faucet.
- A transparent first-stage housing is described as allowing visual filter inspection.
- The listing says the system retains minerals and does not reduce TDS.
- Filter replacement is described as every 6 to 12 months depending on use and water quality.
Reference price: $97.00
Price checked: Nov 14, 2026
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Pros and cons
Pros
- Dedicated faucet, mounting bracket, housings, filters, parts and tubing are listed as included.
- A 1 gpm listed flow rate may suit drinking water and filling cookware without waiting on a pitcher.
- The stated 10,000-gallon capacity and up-to-12-month filter life may reduce cartridge-change frequency compared with shorter-lived options.
Cons
- This system does not reduce TDS, so it is not suited to buyers who need dissolved-solids reduction.
- The stated replacement interval is conditional on water quality and usage, so actual filter life can vary.
Technical specifications
14 specifications| Brand | iSpring |
|---|---|
| Model | US31 |
| Purification method | 3 Stage. Chemical Absorption and Mechanical Filtration |
|---|---|
| Listed capacity | 10000 gallons |
| Filter life cycle | 12 months |
| Maximum flow rate | 1 gpm |
| Installation type | Under Sink |
|---|---|
| Dimensions listed | 13"L x 5.3"W x 14.2"H |
| Weight listed | 5.5 kg |
| Material listed | Combination of materials |
|---|---|
| Power configuration | Ac |
| Upper temperature rating | 100 °F |
|---|---|
| Feed water pressure | 30-70 psi |
| Warranty description | 1 Year Manufacturer |
What to know before buying
Listing details to confirm
The listing describes the unit as AC-powered in one specification field, but its product Q&A says it needs no electricity and operates on water pressure. Treat the power detail as contradictory. It also gives a 12-month filter cycle while elsewhere advising replacement every 6 to 12 months. The listing calls filters NSF/ANSI certified but does not identify the exact certification scope here. Confirm the configuration and certification details for the selected listing.
What’s in the box
Included- Housings
- Filters
- Parts
- Tubing
- Faucet
- Mounting bracket
Who is it for?
A good fit for
- Households seeking an under-sink, three-stage filter with a separate faucet for drinking and cooking water.
- Buyers who want chlorine, sediment, taste and odor reduction while retaining incoming-water TDS.
Less suited to
- Buyers who need reverse-osmosis-style TDS reduction or a stated reduction of dissolved minerals.
- Installations with feed-water pressure outside the listed 30-70 psi range.
Customer reviews on Amazon
- 5 stars
78% 78% - 4 stars
11% 11% - 3 stars
4% 4% - 2 stars
1% 1% - 1 star
6% 6%
Customer feedback highlights ease of installation and use, included parts, water flow and perceived taste or quality improvements. Some customers report little change in water quality, and others describe internal leaks or dripping at factory fittings. For buyers considering this three-stage system, those accounts make careful inspection of connections and realistic expectations about taste and filtration results important. The listing also states that the system does not lower TDS.
Positive themes
- Customers describe installation and everyday use as easy, and report good flow and improved water taste.
Negative themes
- Some customers report internal leakage or dripping from factory fittings.
Mixed feedback
- Reports of water quality differ. Some customers notice improvement while others say the water seems virtually unchanged.
Frequently asked questions
Does the iSpring US31 reduce TDS?
No. The listing says it maintains the incoming water's TDS and retains natural minerals. It points buyers who need TDS reduction toward reverse-osmosis filtration.
How often should the filters be replaced?
The listing gives an interval of 6 to 12 months depending on usage and water quality, while another specification lists a 12-month filter life.
Does the system need electricity?
The product Q&A says it works on water pressure alone and does not require electricity, but a details field lists AC power. This contradiction should be clarified before purchase.
What water pressure does it require?
The listed feed-water pressure range is 30-70 psi.
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