Jim,
I believe that I may be able to assist you very considerably in this matter, at least I hope so.
Where I am located, at least at my cabin along the Elkhorn River north of Fremont, Nebraska, the ground water is very high in Ferrous iron. Ferrous Iron is a divalent ion compound denoted as Fe-2 or Fe-II. The alternative compound is Ferric Iron which is trivalent and denoted as Fe-3 or Fe-III.
If your well water has a high concentration of Ferric Iron or Fe-III, you will usually be able to identify this right away as the water you pump out of the well will have a reddish-orange color and will stain and build up on all of your plumbing fixtures, wash basins and tubs. If it is bad enough, it will stain your clothes in the wash. EDIT: This form of iron can be mechanically filtered out of the water with appropriate cartridge type filters.
If your well water has a high concentration of Ferrous Iron, you will not be able to detect this with the naked eye. You might taste the difference if the concentration is high enough and you are attuned to the "flavor". The water you pump from the well will appear completely clear and absent of any discoloration that you would associate with iron rust. However, the same problems of staining will still occur over a longer period of time. The reason for this is that once the water containing Ferrous Iron is exposed to oxygen and warmer temperatures, a chemical or ionic change occurs and the Ferrous Iron which is dissolved in the water is oxidized or it "rusts" and changes to Ferric Iron. If you pump water containing Ferrous Iron to the surface and fill a clear container with the water and allow it to sit, exposed to warmer temps and oxygen, the water will eventually turn cloudy red or orange and precipitate out to leave a sediment of rust colored 'sludge' at the bottom of the container.
Ferrous Iron cannot be filtered out of the water by normal mechanical filtration methods. It functions like table salt dissolved in water. Once dissolved in water at an ionic or molecular level, it passes through the finest of mechanical filters and only cell membrane walls can stop it.
Ferric Iron, on the other hand, is a larger particle and it precipitates out of the water and becomes a sediment which can be mechanically filtered out.
If you can understand the difference between these two forms of iron, then you can wage battle on the iron itself and eliminate it or remove it from your water.
Before I get into explaining how to do that, I will explain one more item. The smell or odor of rotten eggs from your water. There are several sources and reasons for this odor. I am going to address only one of these as it pertains to Iron.
A certain bacteria exists which thrives on iron. It is its "food source" for a lack of a better terminology. The horrible or unworthy odor you are greeted with is basically bacteria "farts" and the scent of their "poop"! EDIT: This bacteria is resident in the water underground. It is naturally occurring and almost always present at some level. Because of the lack of oxygen and the cooler temperatures underground, you don't notice the effects of this bacteria until you pump the water to the surface and expose it to oxygen and higher temperatures. That is when the rotten egg or sulfur odor becomes noticeable. It is also why the water from the water heater will smell moreso than the cold tap water does.
As disgusting and unpleasant as that sounds, none of this can harm you at the levels that exist in any well. It is all harmless, but it is very distasteful, I will agree.
I am going to stop here and post this much and then I have to reboot my computer as it is giving me fits.
Back in a jiffy!
Gordy