We treat our mine discharges for Fe2/3 and Mn by using a good oxidizer followed by a filtration system (We use sand filters aith a gooch bottom), but for a home system they make these big "tampon" filters that work fine (They need to be changed frequently to keep your pump from rising head pressures.
One of the best oxidizers is Chlorine. Id use a Hypo tank with a system feed . Cl is also a good disinfectant because the Slimes on Fe/Mn waters are high in ulothrix and Chronothrix
These can show up as a type of coliform . They can be kind of disgusting because they can impart a funky iron taste.
You can do this yourself with a swimming pool l feeder and a post Cl filtration unit. Your water will be essentially Fe/Mn free. (At least below a decent level).
Id actually be more concerned about the Manganese in the water. Its been shown to be a serious neural toxicant and has often been associated with non Alzheimer dementia in kids.
At 2.5 ppm. think that your Mn levels will be roughly half (dependent on a kind of " aggressiveness index" of the water)