Fresh water only, and trailered after every use. Yes I know how they work.
Very little point in having an anode then. If its on a trailer an anode is not needed and in fresh water to be effective you would need a magnesium anode anyway. Zinc becomes passivated with an oxide coating in fresh water.
(Magnesium is too reactive to use in salt water)
If i may piggyback, if one went from a saltwater use to freshwater only and the anode is all crusty... should it be replaced or removed?
You need a magnesium anode in freshwater.
The rules regarding anode type are that zinc is only effective in saltwater ( they are made of special high purity zinc which conforms to a US military specification)
Aluminum anodes are suitable for salt water or brackish water. They are made of a special alloy containing among other alloying elements a small percentage of indium.
Magnesium anodes are suitable for fresh water use only. They are made of magnesium containing small percentages of aluminum and zinc
