TO remove iron, I use what they call a birm filter. Essentially the water is aerated with a micronizer, held in a precipitaion tank briefly, and then filtered through a bed of pumicite which gets backwashed from time to time. It involves no chemicals but the micronizer requires a significant flow rate to work at higher pressures. Mine stops sucking air at 40 PSI. There are other systems like the Iron Curtain, that uses an air compressor instead of a micronizer.
I have very hard water so I also have a softener after the iron filter and I use Potassium in it. Potassium will impart some taste so the drinking water then goes through an RO filter.