No chlorine is fine with manganese dioxide filters and it can also help to remove the manganese from the water:
Oxidation increases with chlorination
Chlorine enhances the oxidation ability of water to aid in the removal of manganese.
Chlorination will kill the iron bacteria
Chlorine kills iron bacteria that cause slime growths in pipes and well screens.
Greensand recharges with chlorination
Chlorine may be used to regenerate manganese greensand filters.
Chlorine can be combined with other treatments
Chlorine is sometimes used in combination with other treatments, including potassium permanganate, to remove iron and manganese from water.
However, oxidised iron and manganese can cause damage to a water softener resin bed. To avoid this, you can remove the oxidised iron and manganese before the water enters the softener.
