iSpring US31-NC 3-Stage Under Sink or iSpring US31KF 3-Stage Chlorine Removal? Which iSpring Model to Buy
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You are comparing the iSpring US31-NC and the iSpring US31KF. Both are 3-stage under-sink water filters that retain healthy minerals and do not lower TDS. The primary keyword is ispring us31 nc 3 stage under sink vs us31kf 3 stage chlorine removal. The US31-NC targets chloramine reduction with certified cartridges and includes a dedicated faucet. The US31KF focuses on deep chlorine removal using a true 3-stage carbon block design without a dedicated faucet, connecting directly to your cold water supply.
Key differences
| Aspect | iSpring US31-NC Under Sink Filter | iSpring US31KF Under Sink Filter |
|---|---|---|
| Filtration Focus | Chloramine, chlorine, VOCs, sediments | Chlorine, sediments |
| Certification | NSF/ANSI 58 for chloramine reduction | Not listed |
| Faucet Included | Yes, top-mount installation | No, connects to existing supply |
| Cartridge Design | Standard 2.5x10-inch twist-on cartridges | Reusable housing with carbon block |
| Dimensions | 5.3 x 13 x 14.2 inches | 9 x 15 x 17 inches |
Which one should you choose?
Choose iSpring US31-NC Under Sink Filter if
- You need certified chloramine reduction for municipal water.
- You want a dedicated drinking water faucet installed.
- You prefer standard twist-on cartridge replacements.
Choose iSpring US31KF Under Sink Filter if
- You want to avoid drilling a new hole in your countertop.
- You prioritize deep chlorine removal over chloramine reduction.
- You prefer a reusable filter housing to reduce plastic waste.
Verdict: Choose the US31-NC if you need certified chloramine removal and a dedicated faucet for your drinking water. Pick the US31KF if you want to keep your existing faucet setup and focus on deep chlorine reduction. Both systems retain beneficial minerals and fit under standard sinks.
US31-NC vs US31KF Comparison
Installation method
The iSpring US31-NC features a patented top-mount design that allows you to install the drinking water faucet from above the countertop. This eliminates the need to crawl under the sink for access. In contrast, the US31KF connects directly to your existing cold water supply using standard 3/8-inch compression fittings. It requires no drilling or extra faucet installation. You do not need a plumber for the US31KF. If you prefer avoiding under-sink access, the US31-NC is the better choice for your kitchen layout.
Flow rate capacity
The iSpring US31-NC delivers up to 5 gallons per minute (GPM) for instant water flow. It also has a high capacity of up to 10,000 gallons or 12 months of use. The published specifications for the US31KF do not list a specific flow rate or gallon capacity. You cannot directly compare the speed or duration of water delivery without that data. The US31-NC provides clear metrics for high-volume usage. You can rely on the stated 5 GPM for fast filling of pots or glasses.
Filtration media depth
The US31KF uses a true 3-stage design with a third-stage carbon block filter containing approximately 13 ounces of activated carbon. This is 2.3 times more carbon than typical quick-change twist-on cartridges. The US31-NC uses FP15 and FC15 cartridges with catalytic carbon media. While the US31-NC is SGS-tested for chloramine reduction, the US31KF explicitly highlights its deeper carbon contact time for thorough chlorine absorption. The US31KF offers more carbon mass per stage for deep purification.
Certification standards
The iSpring US31-NC has two cartridges, FP15 and FC15, that are NSF/ANSI 58 certified for safety and performance. The FC15-NC is also SGS-tested for enhanced chloramine reduction against the NSF 42 standard. The US31KF specifications list chlorine removal but do not mention specific NSF/ANSI certifications in the provided data. You can verify the US31-NC meets rigorous third-party testing standards. The US31KF relies on its 3-stage carbon block design without listed certification data.
Physical dimensions
The iSpring US31-NC measures 5.3 inches in width, 14.2 inches in height, and 13 inches in length. The US31KF is larger, measuring 9 inches in width, 17 inches in height, and 15 inches in length. It also weighs 12.3 pounds. The US31-NC has a narrower profile, which may fit better in tighter under-sink cabinets. The US31KF requires more vertical and horizontal space. You should measure your available cabinet space before choosing between the compact US31-NC and the bulkier US31KF.
Which iSpring Under Sink Filter Fits You
Users wanting simple faucet installation
The US31-NC uses a patented top-mount design. You install the faucet from above the countertop. This removes the need to crawl under the sink. The clear housing lets you see captured particles. It retains healthy minerals and does not lower TDS. You get lifetime technical support and a 1-year limited warranty.
Buyers prioritizing deep chlorine reduction
The US31KF features a true 3-stage design. It triples the filtration path for deeper chlorine removal. The third-stage carbon block holds approximately 13 ounces of activated carbon. This reusable housing lasts 5 to 10 years. It connects to your cold water supply with standard 3/8-inch compression fittings. No drilling or extra faucet is required.
Those seeking chloramine and VOC removal
The US31-NC is NSF/ANSI 58 certified for chloramine reduction. It uses SGS-tested catalytic carbon media. This system reduces sediments, chloramine, VOCs, and chlorine. It delivers up to 5 GPM for fast flow. The cartridges are individually wrapped to preserve quality. You benefit from trusted safety and performance for municipal water treatment.
The products compared
iSpring US31-NC Under Sink Filter
Best for: chloramine reduction with high flow
- Filtration Stages
- 3-Stage
- Design
- Under sink
- Certification
- NSF/ANSI certified
- Contaminants Removed
- Chloramine, sediment, VOCs, chlorine
- Installation Type
- Under sink
- Features
- Sediment Filter
View on Amazon: iSpring US31-NC Under Sink Filter Affiliate link
The iSpring US31-NC is a 3-stage under-sink water filter designed for chloramine-treated municipal water. It uses NSF/ANSI 58 certified cartridges to reduce sediments, chloramines, VOCs, and chlorine. The system delivers up to 5 GPM and 10,000 gallons of filtered water. It retains healthy minerals and does not lower TDS. The clear housing lets you monitor captured particles. It features a top-mount faucet installation for easier setup.
Pros
- NSF/ANSI 58 certified for chloramine reduction
- High flow rate up to 5 GPM
- 10,000-gallon filter capacity
- Clear housing for visual monitoring
- Top-mount faucet installation
Cons
- Only 1-year limited warranty
- Does not remove dissolved solids like RO systems
- Requires countertop drilling for faucet
Good fit if
- You have chloramine-treated municipal water
- You want to retain healthy minerals
- You prefer easy top-mount installation
Skip if
- You need to remove dissolved solids
- You want a longer warranty period
- You prefer under-counter faucet installation
Verdict: iSpring US31-NC Chloramine Removal Filter is a solid choice for households needing effective chloramine reduction without the waste of reverse osmosis. It suits those who value high flow rates and easy installation over mineral removal capabilities.
iSpring US31KF Under Sink Filter
Best for: chlorine removal without mineral loss
- Filtration Stages
- 3
- Design
- Under sink
- Certification
- NSF standards
- Contaminants Removed
- Sediment, rust, dirt, odor, chlorine
- Installation Type
- Under sink
- Features
- Chlorine Reduction, Sediment Filter
View on Amazon: iSpring US31KF Under Sink Filter Affiliate link
This iSpring system uses a true three-stage carbon block design to remove chlorine from under-sink water. It features transparent housings so you can see sediment buildup and filter changes in real time. The unit connects to existing cold water lines without drilling or adding a faucet. It retains beneficial minerals while reducing contaminants. It suits households wanting deep chlorine removal without the complexity of reverse osmosis.
Pros
- True 3-stage carbon block filtration extends contact time for thorough chlorine removal
- Transparent housings allow you to monitor sediment buildup and filter color changes
- Connects to existing cold water supply with standard 3/8-inch fittings, requiring no drilling
- Reusable housing holds approximately 13 ounces of activated carbon
Cons
- Installation takes more time and effort than twist-on disposable filters
- Only removes chlorine, not chloramine or other contaminants
- Requires a 17-inch vertical clearance under the sink
Good fit if
- You want to reduce chlorine taste and odor without lowering mineral content
- You prefer to see filter performance changes through transparent housings
- You have an existing cold water line and want to avoid drilling
Skip if
- You need to remove chloramine, bacteria, or PFAS
- You want a quick twist-on filter replacement process
- You need a system that adds a dedicated faucet
Verdict: iSpring US31KF 3-Stage Chlorine Filter is a practical choice for users who want to improve water taste by removing chlorine while keeping minerals intact. It works best for those willing to perform a standard under-sink installation to benefit from its transparent monitoring features.
Specifications side by side
| Spec | iSpring US31-NC Under Sink Filter | iSpring US31KF Under Sink Filter |
|---|---|---|
| Filtration Stages | 3-Stage | 3 |
| Design | Under sink | Under sink |
| Certification | NSF/ANSI certified | NSF standards |
| Contaminants Removed | Chloramine, sediment, VOCs, chlorine | Sediment, rust, dirt, odor, chlorine |
| Installation Type | Under sink | Under sink |
| Features | Sediment Filter | Chlorine Reduction, Sediment Filter |
| Use | not stated | Kitchen |
| Dimensions | 13 × 5.3 × 14.2 inches | 15 × 9 × 17 inches |
| Weight | not stated | 12.3 pounds |
| Size | Standard | not stated |
| Color | Pure White - Plus | not stated |
| Model | US31-NC | US31KF |
Frequently asked questions
Does the iSpring US31-NC remove chloramine?
Yes, the iSpring US31-NC is designed for chloramine reduction. It targets chloramines effectively while maintaining high flow rates. This makes it a practical choice for households needing to remove chloramine without the waste associated with reverse osmosis systems. You get clear monitoring through its transparent housing.
Is the iSpring US31KF better for chlorine removal?
The iSpring US31KF focuses on chlorine removal while keeping minerals intact. It is a practical choice for users who want to improve water taste. This filter retains healthy minerals and does not lower total dissolved solids. It suits those willing to perform a standard under-sink installation.
What are the dimensions of the iSpring US31-NC?
The iSpring US31-NC measures 5.3 inches in width, 14.2 inches in height, and 13 inches in length. Its standard size fits typical under-sink cabinets. The compact footprint helps you save space in your kitchen. You can easily install it without needing extensive cabinet modifications or extra room.
How large is the iSpring US31KF compared to the US31-NC?
The iSpring US31KF is larger, measuring 9 inches in width, 17 inches in height, and 15 inches in length. It also weighs 12.3 pounds. This model requires more cabinet space than the US31-NC. You should verify your under-sink area can accommodate these larger dimensions before purchasing.
Does the US31-NC use a top-mount faucet design?
Yes, the iSpring US31-NC features a patented top-mount design. You install the drinking water faucet from above the countertop. This eliminates the need to crawl under the sink for access. It simplifies the installation process significantly compared to traditional under-sink faucet setups that require lower cabinet access.
Does the US31KF have sediment filtration?
Yes, the iSpring US31KF includes sediment filtration as part of its features. It is a 3-stage filter that removes chlorine and sediment. This helps protect your plumbing and appliances from particles. The system retains minerals while improving taste and clarity through its multi-stage filtration process.
Can I see the filter status on the US31-NC?
Yes, the iSpring US31-NC has a clear housing. This lets you see captured particles inside the filter. You can visually monitor the filtration status without opening the unit. This feature helps you know when to replace the filter based on visible sediment buildup rather than just time.
Does either model lower TDS levels?
No, neither model lowers total dissolved solids. Both filters retain healthy minerals in your water. They focus on removing chlorine, chloramine, and sediment. This means your water stays mineral-rich while improving taste and safety. You do not need to worry about removing beneficial minerals during filtration.