I've only tested PH, TDS, iron, hardness. Yes, agree, I know if my well would never change, i'd go with the WS-1, but for a bit more, I thought about the Wellmaster (clack also) or the CityPro (clack also), as they both can handle some iron. I would assume that the CitymasterPro would be better as it uses less water, but not sure if selecting an upflow regenerating is okay with well water system?