Neuturlizer then either an iron filter or softener?
Has the plumber that you paid done this kinda thing before?
Part of the question that you need to ask your self is what kind of water do you want to have when all is done..
Some are cool with hardness, others would like that out as well..
The neuturlizer may pull some of the iron out of the water... here as the ph is corrected to 7.1 if there is Iron in the water it will fall out of the water.. not all but some ..
but add a grain or two of hardness to the water.