---
product_id: 213775088
title: "iSpring FG15B-KS Premium Quality Super Capacity GAC and KDF Carbon Filter Replacement Cartridge for Direct Connect Under Sink Water Filtration System US21B & US21B-CPB, 10” x 4.5”"
brand: "ispring"
price: "₨37438"
currency: LKR
in_stock: true
reviews_count: 8
category: "I Spring"
url: https://www.desertcart.lk/products/213775088-ispring-fg15b-ks-premium-quality-super-capacity-gac-and-kdf
store_origin: LK
region: Sri Lanka
---

# 80,000 gal capacity Fits standard 10" systems Multi-contaminant removal iSpring FG15B-KS Premium Quality Super Capacity GAC and KDF Carbon Filter Replacement Cartridge for Direct Connect Under Sink Water Filtration System US21B & US21B-CPB, 10” x 4.5”

**Brand:** ispring
**Price:** ₨37438
**Availability:** ✅ In Stock

## Summary

> 💧 Elevate your tap water game—because your family deserves nothing less!

## Quick Answers

- **What is this?** iSpring FG15B-KS Premium Quality Super Capacity GAC and KDF Carbon Filter Replacement Cartridge for Direct Connect Under Sink Water Filtration System US21B & US21B-CPB, 10” x 4.5” by ispring
- **How much does it cost?** ₨37438 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.lk](https://www.desertcart.lk/products/213775088-ispring-fg15b-ks-premium-quality-super-capacity-gac-and-kdf)

## Best For

- ispring enthusiasts

## Why This Product

- Trusted ispring brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Seamless Compatibility:** Designed as the official 1st stage replacement for iSpring US21B systems and fits all standard 10" under-sink or whole-house filters.
- • **Endless Clean Water Flow:** Delivers up to 80,000 gallons of crisp, contaminant-free water—stay refreshed without interruption.
- • **Long-Lasting Performance:** Enjoy 8-12 months of hassle-free filtration with easy cartridge replacement—never compromise on water quality.
- • **Trusted Support from Atlanta:** Access expert tech and customer service anytime to maximize your filtration experience and peace of mind.
- • **Powerful Multi-Contaminant Defense:** Effectively removes chlorine, lead, mercury, hydrogen sulfide, chloramines, and more for pure, safe hydration.

## Overview

The iSpring FG15B-KS is a premium 10" x 4.5" GAC and KDF carbon filter cartridge engineered for superior removal of chlorine, heavy metals, hydrogen sulfide, chloramines, and other contaminants. With an impressive 80,000-gallon capacity, it fits standard under-sink and whole-house filtration systems, including iSpring US21B models. Designed for 8-12 months of reliable use, it preserves essential minerals while delivering fresh, odor-free water. Backed by NSF certification and responsive Atlanta-based support, this filter ensures your water is clean, safe, and great tasting—making it a must-have upgrade for health-conscious professionals.

## Description

Made of premium GAC and KDF, this 10” x 4.5” compound carbon filter FG15B-KS is the official 1st stage replacement filter cartridge for iSpring direct connect Point-of-Use(POU) under sink water filter system US21B. It also fits standard 10" under sink water filter or whole house water filtration systems. Designed to effectively remove chlorine, lead, mercury, iron, hydrogen sulfide,chloride, chloramines, herbicides, odors, and other contaminants or impurities, FG15B-KS can team up with carbon filters like iSpring FC15B to create a reliable shield that protects you and your family from ingesting harmful chemicals or contaminants in your tap water.

Review: The Holey Grail - Ever since moving to a home with a well, I've been searching for a whole-house filter to neutralize the local sulfuric sediment which darkens the water and causes rotten egg smell. I've tried all sorts of filters from standard carbon block to fine pleat to basic KDF and found them all lacking in one way or another. But now I've finally found a filter which ticks all the boxes. Flow Rate - Much better than other KDF filters I've tried. It can easily run multiple sinks and showers simultaneously. Sediment Filtration - I don't see a micron rating anywhere, but it does a fine job stopping small particles which slip through my 40 micron spin-down filter. Smell Reduction - A new filter totally eliminates the rotten egg smell caused by sulfuric compounds in my water supply. Longevity - This filter is rated for 8-12 months and it certainly can run that long without any noticeable clogging or pressure loss. However, the sulfur smell began slowly creeping back in after about 6 months and became bad enough to trigger a replacement by 10 months. Design and Installation - Unlike other filters I've tried, the flow goes bottom to top rather than outside to inside. This means that the filter must be installed right-side-up, but there's only one seal to worry about because the bottom center is fully closed off. Overall this filter meets all my expectations at a reasonable price, and I'm very happy to finally have odorless tap water.
Review: Terrific! - Installed this into a GE 10” whole house filter housing last week. So far no issues and the water is clear and clean. Chlorine was eliminated and the water feels better showering. Some call it magical but I hope it lasts a few months. So far so good and I’ll buy another one.

## Features

- [Superb Filtration Performance] FG15B-KS 10” x 4.5” compound filter is designed to effectively remove chlorine, lead, mercury, hydrogen sulfide, iron, chloride, chloramines, herbicides, odors, and other contaminants or impurities.
- [Water Health Warrior] Teaming up with carbon filters like iSpring FC15B, this filter is super powerful to remove the unpleasant taste or odor left in chlorinated water while maintaining the protection benefits of chlorine in water disinfection. They also tackle problems like turbidity, cloudiness, colors, bad taste, and odors like hydrogen sulfide that smells like rotten eggs. A reliable shield that protects you and your family from ingesting harmful chemicals or contaminants in your tap water.
- [Great Compatibility] Official 1st stage replacement filter cartridge for iSpring direct connect Point-of-Use(POU) undersink water filtration system US21B. Fits standard 10" undercounter or whole house water filtration systems. Individually sealed for freshness.
- [Exceptional Filter Life] Based on the contaminant levels in source water and your water use, we suggest that you change your filters every 8-12 months for best filtration performance. Hassle-free filter cartridge replacement is a breeze!
- [TDS Note] Please be noted that the system for which this filter works is NOT designed to reduce Total Dissolved Solids(TDS) removal and instead keeps essential minerals in your water. If you are interested in a filter that significantly reduces TDS, please consider our iSpring Reverse Osmosis (RO) systems RCC7 series or tankless RO500.
- [Peace-of-Mind Support] We offer tech and CS support via phone and email from Atlanta, GA. Contact our responsive and professional team for product selection to suit your water filtration needs and after-sale support to maximize your user experience. Now, and years to come, we will be right here and ready to help.
- Capacity: 80000 gallons

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Brand | iSpring |
| External Testing Certification | NSF |
| Material | KDF+GAC |
| Product Benefits | Provides superb filtration performance, removing various contaminants and impurities for clean and safe drinking water Product Benefits Provides superb filtration performance, removing various contaminants and impurities for clean and safe drinking water See more |
| Product Dimensions | 4.5"D x 4.5"W x 10"H |
| Set Name | US21B |

## Product Details

- **Brand:** iSpring
- **External Testing Certification:** NSF
- **Material:** KDF+GAC
- **Product Dimensions:** 4.5"D x 4.5"W x 10"H

## Images

![iSpring FG15B-KS Premium Quality Super Capacity GAC and KDF Carbon Filter Replacement Cartridge for Direct Connect Under Sink Water Filtration System US21B & US21B-CPB, 10” x 4.5” - Image 1](https://m.media-amazon.com/images/I/71cspyuJUDL.jpg)

## Customer Reviews

### ⭐⭐⭐⭐⭐ The Holey Grail
*by B***2 on October 12, 2025*

Ever since moving to a home with a well, I've been searching for a whole-house filter to neutralize the local sulfuric sediment which darkens the water and causes rotten egg smell. I've tried all sorts of filters from standard carbon block to fine pleat to basic KDF and found them all lacking in one way or another. But now I've finally found a filter which ticks all the boxes. Flow Rate - Much better than other KDF filters I've tried. It can easily run multiple sinks and showers simultaneously. Sediment Filtration - I don't see a micron rating anywhere, but it does a fine job stopping small particles which slip through my 40 micron spin-down filter. Smell Reduction - A new filter totally eliminates the rotten egg smell caused by sulfuric compounds in my water supply. Longevity - This filter is rated for 8-12 months and it certainly can run that long without any noticeable clogging or pressure loss. However, the sulfur smell began slowly creeping back in after about 6 months and became bad enough to trigger a replacement by 10 months. Design and Installation - Unlike other filters I've tried, the flow goes bottom to top rather than outside to inside. This means that the filter must be installed right-side-up, but there's only one seal to worry about because the bottom center is fully closed off. Overall this filter meets all my expectations at a reasonable price, and I'm very happy to finally have odorless tap water.

### ⭐⭐⭐⭐⭐ Terrific!
*by T***E on March 22, 2023*

Installed this into a GE 10” whole house filter housing last week. So far no issues and the water is clear and clean. Chlorine was eliminated and the water feels better showering. Some call it magical but I hope it lasts a few months. So far so good and I’ll buy another one.

### ⭐⭐⭐⭐ Excellent - Best filter used to date -- UPDATED
*by K***R on December 18, 2020*

I've been searching for decent filters for years. I had one that worked okay, but then the company sold that division (GE) and it turned to cheap junk like most others I tried. Some of the other filters I tried left sediment through, odors, iron (rust) and some I think even added rust to my water supply. So far, this one is the best I've seen. Immediately the rust stains in the toilets stopped appearing (I had to remove them every week before, and I have city water so no idea where rust was coming from) and it has been over a month now with no reappearance. The design of the filter is really interesting so it maximizes the surface area while filtering and has elements built in that eliminate algae type gunk from growing in the filter. I checked the flow as installed new and it was slightly better than other filters when new (about 1 GPM more). These are supposed to last longer than the cheaper ones so I will test the flow at regular intervals and see if it degrades or not, but so far so good. Yes, this is more expensive than the last ones I used but if it lasts longer, continues to either remove rust or at least not add it, keeps algae scum from growing in the filter and doesn't disintegrate over time (yes, I had this before and was told by the manufacturer this is normal and shouldn't be harmful, but I don't like the idea of drinking carbon particles) then over time it may even be less expensive, and certainly give better quality and less maintenance, then it's the hands down winner. As I test this I'll update more if anything disappoints. As a side note I did contact the company with a few questions and their response was prompt and meaningful, as well as a few months later they reached out to make sure the product was still performing to my satisfaction. So far, quality all around. 6/29/2022 UPDATE: After using these filters for the last couple of years I had a failure of one that after 6 months released carbon particles into my water system. It plugged up faucets, washing machine inlet, internal solenoids of the washing machine and blackened toilets, leaving a layer of black "silt" in the toilet tanks. After contacting the company and getting past the initial "you need to flush new filters first" comments (I did state that it was in use for 6 months), the company stepped up and offered to replace the filter with a new one. Honestly I expected the typical run-around we've all experienced. Although there was a filter failure, I realize it does happen, and how it is resolved not only tells me that the warranty is real but also about the culture of the company. If they treat you respectfully and are willing to stand behind a product that means a lot.

## Frequently Bought Together

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*Product available on Desertcart Sri Lanka*
*Store origin: LK*
*Last updated: 2026-03-01*