





💧 Elevate your whole house water game—because clean water is the new luxury.
The iSpring FM15B is a high-capacity, 10"x4.5" replacement water filter cartridge designed for whole house systems like the iSpring WGB21BM. It effectively reduces iron from 3.0 ppm to 0.01 ppm and manganese from 1.0 ppm to 0.01 ppm, delivering cleaner, healthier water. Engineered for high flow rates (4-8 GPM) with minimal pressure drop, it operates efficiently across a wide pH and temperature range. Certified to NSF/ANSI and FDA standards, this durable filter lasts up to 30,000 gallons—three times longer than green sand alternatives—and comes with lifetime US-based tech support and an extended warranty for peace of mind.











| Brand | iSpring |
| External Testing Certification | ANSI, NSF |
| Material | Carbon Fiber |
| Product Benefits | Reduces iron and manganese in water |
| Product Dimensions | 4.5"D x 4.5"W x 10"H |
| UPC | 810004171855 |
J**Z
I works
I have a cabin on Lake Michigan and the water from our well is so hard that it chips your teeth when you drink it. (sorry for the dad joke) Please note that this is a seasonal cabin and is not winterized. None the less, this filter does a great job in cutting down of the yellowing of toilet bowls and shower walls. No filter can eliminate 100% of the iron or manganese in the water (need a good water softener to do it completely) , but it cuts down on the times between cleanings. We would need to clean the residue from the toilets before filter at least once a week, now it's every 2 months. White shower walls, now once a season. This filter along with I-Springs activated charcoal filter has eliminated the need for us buying drinking water.
R**K
works well long lasting filter
works well, long lasting
L**A
HUGE Difference with Well Water, No longer Slippery or Smelly
I know we should get a comprehensive water test for our well water, but for $200-$300 that's steep. We knew from simple testing that it was high pH about 8.5 with limestone in our area and suspected iron content because that's common to wells in our area. We were using a dual whole house system with 5 micron sediment filter followed by carbon filter. Water was usable but slippery and smelled like metal. Confirmed clear water iron issue (ferrous iron) by the rust color in commodes over time. Ferrous iron is clear in water, but reacts with oxygen in the air to form the colored sediment/stains. We added a spin down 40 micron sediment filter before the other filters. After 3 months flushed the spin down filter and almost nothing in it. Doesn't seem to be a sediment issue, confirmed later by replacing the 5 micron sediment filter with this FM15B Iron and Manganese filter. The silt in the housing was the same as before the spin down sediment filter, so we didn't really need the 5 micron sediment filter. After a few days on the Iron filter - WoW! Water no longer slippery, smells a lot better, soap washes off easily in the shower, almost like having a water softener! We'll have to see how long this filters lasts since we don't really know the degree of iron contamination. So far, very happy with this iron and manganese filter and wish we had done it sooner!
K**N
Only lasted a week
I was so excited about this filter working to keep the iron out of my water, but it only lasted about a week. The smell came back and the staining of my toilet, shower, and sink is back and seems worse than before. I put the filter in on June 1st and it seriously only lasted a week with clearer water and no smell. So disappointed.
K**Z
Perfect. Removes Iron from well water
Got a well? This is all you need. I’ve purchased 2 and am about to order my third. I usually change my filters (including my refrigerator) every 6 months. Apparently I forgot to change it. I just replaced after 1 year and it was still removing Iron! The evidence was in the Big Blue filter holder. Not only was the filter itself full pf the reddish/brown particles left from iron removal, but so was the holder! Oh my! I realized I was overdue to change the filter because my water pressure dropped a bit. I could tell when taking a shower. Full disclosure: for about 3/4 of the year I was the only one home. If more people were us the water I would have noticed the pressure drop much sooner. Bottom line: I found this filter works great IF you have a well and high Iron.
K**N
This gets rid of slimy black bacteria growth!
I bought this filter when I read that the slimy black stuff growing like crazy in all of my faucets was caused by bacteria that feed on iron and manganese. It would grow and block the holes in the aerators, causing water to start spraying in weird directions or even choking off holes entirely, and this would happen within a couple of weeks of cleaning. I added this to a standard 2 filter set from iSpring that I purchased before learning about this filter. With this addition, the bacteria have gone away, and I no longer have this problem anymore. It's fantastic. This is in an apartment in Brooklyn.
K**H
Works well depending on levels of iron and other minerals in your water
Does a great job filtering our water. Does need to be replaced about every 6-8 weeks because of the high amounts in our well
J**.
no more metallic aftertaste
I ordered an ispring whole house filter system WGB21B in may of 2020 for a summer house in northern Wisconsin using well water. It cleared up the water amazingly well with a sediment filter FP15B and a cto filter FC15B. The water still had a slight metallic aftertaste. This year the taste was noticeably worse so I added another filter canister and an ispring iron and magnesium filter FM15B. The aftertaste is completely gone. Excellent products that work surprisingly good. I called Isping customer service with a technical question and received a call answering my question from NICK and a follow-up call from MICHELLE. Great customer service!
Trustpilot
1 month ago
2 weeks ago