Iron & Manganese Removal in Massachusetts

Telling the two apart

Iron and manganese travel together in Massachusetts groundwater but leave different signatures. Iron stains orange, red or rust brown — on the porcelain, in the tub, on white laundry. It's noticeable above roughly 0.3 mg/L. Manganese stains black, dark grey or brownish black, and shows up as specks in the ice, dark streaks in the dishwasher, and grey laundry that used to be white. Manganese stains at a far lower threshold, from about 0.05 mg/L, which is why a water that tests 'low' for manganese can still be ruining your wash.

Dissolved versus oxidised — the question that sets the system

Run a glass from the tap. If it's clear when drawn and turns orange after sitting, the iron is dissolved — ferrous — and a plain filter will pass it straight through, because you cannot filter something that is in solution. If it comes out of the tap already orange and cloudy, it's already oxidised — ferric — and it's particulate, which a filter can catch. Most Massachusetts well water is the first case. That's why the treatment is oxidation followed by filtration: convert the dissolved metal into a particle, then remove the particle. Skipping the oxidation step is the single most common reason an iron filter someone else installed isn't working.

Why softeners get destroyed by iron

A water softener will remove a small amount of dissolved iron as a side effect, and plenty of installers rely on that. It's a mistake above about 0.3 mg/L. Iron fouls the ion exchange resin, coating it so it can't do the job it was bought for, and the softener quietly stops softening while continuing to consume salt. If you have both iron and hardness — extremely common on Massachusetts wells — iron removal has to come first in the train. If your softener is only a few years old and no longer keeping up, iron fouling is the first thing worth checking.