Remove stubborn iron, manganese and sulphur without chemicals. Incoming raw water passes through a compressed pocket of air in the first tank. The air precipitates the iron into a solid for removal as it passes through the filter’s media bed in the second tank. The media acts as a catalyst in the reaction between iron and oxygen, causing more the iron to precipitate. Periodic automatic regeneration replenishes the supply of air and cleans the media of filtered iron.