A. We get more questions about iron than any other water problem. The method depends on how much iron is in your system and how fine the particles are. A test you can do yourself would be to fill a clear glass with water and let it sit for 15-20 minutes. If the iron settles to the bottom then a cartridge type filter (5 micron or smaller) should be able to remove the majority of the iron particles. If the particles remain suspended then a filter won't help.