Lime-hard water will be found in regions that have a high level of limestone in the ground. Fl is a great example. You will get a scaley lime residue on showerheads, ect. Iron will make the water taste a little bit like you cut your lip. Blood has high iron is why I say this. You can have orange/rusty stains in the tub or under your outdoor fawcet. Ther is also a bacteria that loves iron that can leave this staining. Like for example, our last home. We had high levels of lime and the iron bacteria. I was able to use bleach with much success because our iron levels weren't too high. If it is high, with bleach you can get rusty looking stains on cloths. We HAD to use either calgon with the detergent or borax with it to get the water soft enough for the detergent to work properly. Our neighbor had a more shallow well and had super high iron levels. So bad, her hair was orange. Our well was really deep and you couldn't even smell the rotten eggs/sulpher like all of the neighbors couuld. Yea, Fl has nasty water!
You will just add the softner to the detergent. The box will have exact instructions. Now calgon really targets lime. It won't remove the existing buildup, but will prevent further setteling of the mineral/s on the materials being washed. Their website is full of awsome info!
The additaves you listed sounded just fine to me. I have always used oxy and spray stain treaters.
Do you have a dispencing drawer or one in a tl'er? What kind of washer is it?
I have never noticed a problem with our regular laundry, but when I added bleach to my diaper laundry, I got funky orangish laundry tabs/Aplix on my BG AIOs! No other part is stained--could this be from iron in our water? And what can I do to get it out? I was looking to destash my smalls soon as DS has nearly outgrown them, but with this rusty looking Aplix I'm not sure I'd have much luck :/