We have a heavy duty iron filter, and a softener. The iron in this area is off the charts. On one end of this county, where we live, there is really high iron. On the other side, it's high sulfur. There are areas with good water, but that's not where we live. I have to say, the aerator does an excellent job. It hasn't given us any problems until now, and this is along the lines of routine upkeep. The filter medium does have to be replaced every so many years. I just didn't realize how many years it's been since it was last done.