Aeration is often used to remove iron by oxidizing the iron from the ferrous (Fe⁺²) to the ferric (Fe⁺3) oxidation state. This reaction is often expedited by using a strong oxidizing agent such as chlorine which increases the overall rate of oxidation. 

While aeration towers are a relatively effective means of removing iron, they are generally ineffective at a pH of less than 9.0. For applications where manganese creates a potential deposition problem, it may be necessary to use manganese zeolite (green sand) filters.