Test for iron, manganese, pH and hardness before buying treatment. Dissolved iron, oxidized iron and iron bacteria can require different treatment trains.
Why iron creates orange stains
Ferrous iron can be clear while dissolved, then oxidize after exposure to air and leave orange-brown deposits on sinks, toilets and laundry. Ferric iron may already appear as visible rust-colored particles.
Iron bacteria can complicate the picture
Slimy orange deposits, swampy odor or persistent fouling can indicate iron bacteria rather than dissolved iron alone. Treatment then becomes a sanitation and filtration problem, not just a softener-sizing problem.
Test before choosing treatment
A useful well-water panel should include iron, manganese, hardness and pH at minimum. High iron can overwhelm a softener and may require dedicated oxidation/filtration upstream.