iSpring US31 Classic 3-Stage Under Sink Water Filtration System for Drinking, Tankless, High Capacity, Sediment GAC Carbon (Newest Version)
-6%
$127.99
$135.99
About this item
- [Classic Drinking Filter]: The water undergoes a three-stage purification process: PP sediment filtration, GAC carbon filter and a unique CTO filtration in the 3rd layer. This system efficiently removes common drinking water sediments such as dust, sand, particles, dirt, and rust. Additionally, it effectively eliminates heavy metals, harmful chemicals, Chloramine, cloudiness, colors, chlorine taste, and odor. It's important to note that this under sink water filtration system DOES NOT lower TDS value but preserves the healthy minerals in your water. Enjoy pure, great-tasting water with essential minerals intact.
- [Fresh Healthy Water Supplier]: The on-demand fast flow rate of the iSpring US31 allows it to meet the widest possible range of needs in your home. Up to 20x more effective than the common water pitcher dispenser. Flow Rate: Up to 1GPM depending on source water pressure. Maxim Pressure: 90psi. It washes fresh produce like fruit and vegetables, brings health protection, can provide your entire family with delicious, clean water straight from your tap.
- [Excellent Quality and Design]: Features beautiful European-designed brushed nickel all-metal faucet and clear see-through 1st stage housing. Clear see-through 1st stage housing makes filter inspection a snap. Manufactured to comply strictly with FDA standards and tested by independent third party against NSF/ANSI standards (42, 53, 61) for water quality, material safety and structural integrity.
- [Easy to Install and Maintain]: Designed for hassle-free installation and maintenance, the system includes a high-capacity sediment filter, GAC filter, and CTO carbon filter. The sediment filter protects and extends the life of your system, while the GAC and carbon filters efficiently remove harmful contaminants. Filters should be replaced every 6 to 12 months, depending on water quality.
- [TDS Note and Customer Services]: This under sink water filter will not reduce the TDS of the incoming water. Instead, it keeps the healthy minerals in your water. If you are interested in a filter that removes TDS, please consider a iSpring reverse osmosis system.Backed by a 1-year Manufacturer with lifetime support from Atlanta, GA USA. For any issue or concern, please don't hesitate to contact us.
Frequently Bought Together

iSpring US31 Classic 3-Stage Under Sink Water Filtration System for Drinking, Tankless, High Capacity, Sediment GAC Carbon (Newest Version)
$127.99
-6%
$135.99
$135.99
- Availability: In Stock
- Model: US31
- Manufacturer: iSpring
- Product Dimensions: 13.00"L x 14.50"W x 6.00"H
- Product Weight: 13.00 LB
Reviews with images
Write Review
john perotti | 
2021-06-22
I Purchased (2) 3 Stage under sink filter systems, had a problem with an O ring Sean in Customer Service Sent me replacement O rings Immediately. I have one unit on my Ice maker and the other unit under the sink as my drinking water. The water quality and taste are the best we have had in years. I am so impressed i purchased a Whole House 3 stage filter unit for our RV.
I have to say both the Quality of the Filter Systems and the After Sale Service provided by Sean in Customer Service are the best.
Thank you john p

2021-06-22
I Purchased (2) 3 Stage under sink filter systems, had a problem with an O ring Sean in Customer Service Sent me replacement O rings Immediately. I have one unit on my Ice maker and the other unit under the sink as my drinking water. The water quality and taste are the best we have had in years. I am so impressed i purchased a Whole House 3 stage filter unit for our RV.
I have to say both the Quality of the Filter Systems and the After Sale Service provided by Sean in Customer Service are the best.
Thank you john p
Norm L. | 
2020-07-19
Lacking a basement and other workable access to the whole-house cold water supply, I am using two under-sink US31's in my seasonal cabin to treat the kitchen and master bath cold water lines. (I am using the Big Blue WGB32BM system at the hot water heater, to treat the whole-house hot water.)
Our US31 systems have greatly improved the quality of our cold water. I am extremely impressed by the quality of each of these iSpring products -- the materials and construction are first-rate.
I am also BLOWN AWAY by their customer service and product support. My installation requirements were complicated by the set-up of our cabin, so I had some questions along the way. Customer support professional Don Huie answered all my questions, sent me additional water line fittings (elbows, etc.) to help me finish my job right. He even phoned and texted me to make sure everything was working out. Like I said, BLOWN AWAY.
(I modified the typical installation to have *all* of the cold water running through my US31 filters, and out to the faucets… not simply out to a drinking faucet. Which reduces the flow rate to 1.5 gpm, but that's plenty to wash hands & dishes with. Much better than our previous off-color water with traces of sediment!)
Because of my double-wide's not-so-sturdy cabinetry, I had to design and construct additional framing to mount my systems on (they weigh over 20 pounds when filled with water.) But hey, that’s what DIY fun is all about, right?
Bottom line, it's all working out like I hoped it would. I am very pleased with this purchase.

2020-07-19
Lacking a basement and other workable access to the whole-house cold water supply, I am using two under-sink US31's in my seasonal cabin to treat the kitchen and master bath cold water lines. (I am using the Big Blue WGB32BM system at the hot water heater, to treat the whole-house hot water.)
Our US31 systems have greatly improved the quality of our cold water. I am extremely impressed by the quality of each of these iSpring products -- the materials and construction are first-rate.
I am also BLOWN AWAY by their customer service and product support. My installation requirements were complicated by the set-up of our cabin, so I had some questions along the way. Customer support professional Don Huie answered all my questions, sent me additional water line fittings (elbows, etc.) to help me finish my job right. He even phoned and texted me to make sure everything was working out. Like I said, BLOWN AWAY.
(I modified the typical installation to have *all* of the cold water running through my US31 filters, and out to the faucets… not simply out to a drinking faucet. Which reduces the flow rate to 1.5 gpm, but that's plenty to wash hands & dishes with. Much better than our previous off-color water with traces of sediment!)
Because of my double-wide's not-so-sturdy cabinetry, I had to design and construct additional framing to mount my systems on (they weigh over 20 pounds when filled with water.) But hey, that’s what DIY fun is all about, right?
Bottom line, it's all working out like I hoped it would. I am very pleased with this purchase.
Adam Bourget | 
2020-06-05
Installation was straight forward. I had the whole thing done in under an hour, which is pretty good since I typically move pretty slow through installs, making sure I complete each step appropriately while checking for leaks along the way.

2020-06-05
Installation was straight forward. I had the whole thing done in under an hour, which is pretty good since I typically move pretty slow through installs, making sure I complete each step appropriately while checking for leaks along the way.
M. Jeffery Kallis | 
2020-05-26
Very tasty and clean water :). They include parts for several different water supply options.

2020-05-26
Very tasty and clean water :). They include parts for several different water supply options.
Pennie Roberts | 
2020-05-23
So far pretty darn good. I have had this filter system for about 3 months now.

2020-05-23
So far pretty darn good. I have had this filter system for about 3 months now.
Christie Schwary | 
2020-05-21
Plain and simple, my family just drinks way more water now. Very happy customer.

2020-05-21
Plain and simple, my family just drinks way more water now. Very happy customer.
Barbara Turner | 
2020-05-18
The main installation was pretty straight forward and easy. Water tastes good!

2020-05-18
The main installation was pretty straight forward and easy. Water tastes good!
Robert Harvey | 
2020-04-21
Installed in less than an hour and easily delivered it's advertised gpd. Quiet.

2020-04-21
Installed in less than an hour and easily delivered it's advertised gpd. Quiet.
0 0 | 
2020-04-05
I was considering a couple options that I saw earlier but when I saw how much money I could save on this, I decided to go through with the purchase. The kit was missing some fittings so I had to call for help. iSpring CS rep was so polite and professional; took care of my problem quickly. 5-star for the product and the customer service!

2020-04-05
I was considering a couple options that I saw earlier but when I saw how much money I could save on this, I decided to go through with the purchase. The kit was missing some fittings so I had to call for help. iSpring CS rep was so polite and professional; took care of my problem quickly. 5-star for the product and the customer service!
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Start Download
US31 Manual
How to install
Replacement Filters & Parts
Filters:
Fittings:
Pipes:
Does this system require electricity to operate?No, the US31 under-sink water filtration system does not require electricity. It works on water pressure alone. How much water pressure is required for it to work?The feed water pressure should be: 30-70 psi How long do the filters last before needing replacement?The filters should be replaced every 6 to 12 months, depending on usage and water quality. This ensures optimal performance and water quality. Will it reduce TDS?No, this under-sink water filtration system does not reduce TDS levels. Instead, it maintains the TDS of the incoming water, preserving essential minerals. If TDS reduction is necessary, we recommend considering an iSpring reverse osmosis system. |