Iron filter vs. water softener

I have problems with iron staining in all my sinks and toilets. I thought I needed to replace my very old water softener that doesn't cycle correctly any more. But the guy who installs water softeners tested my water and said I have 4 parts iron, and water softeners only take out 2 parts. He recomended that if I could choose only one of them, an iron filter with potassium is the way to go instead of a water softener. I don't know anything about iron filters. Is he correct in saying that water softeners won't take out all the iron, and an iron filter would be better for me?

I would go with his recommendation. If Iron and not hardness is the problem its a no-brainer.

He's wrong and since you mention "potassium" he is proposing a manganese greensand filter and the industry is trying to get away from them due to Potssium Permanganate being a serious poison. I sell softeners built to remove up to 5 ppm of iron, and whatever hardness is in the water. I've been doing it for over 20 years. And I sell them for much less than a local dealer can.

You're better off replacing the softener.

What is the hardness?

I don't know what the hardness is. He didn't say. But we do get deposits on dishes in the dishwasher.