The anode guide - which anode in which water?

The choice of anode plays a major role in the protection capacity regardless of whether it concerns seawater, brackish water or fresh water. We clarify what applies where.

  • Salt water

Both zinc and aluminum work well in seawater. However, when it comes to a higher salinity, aluminum is much more effective. It requires about 1/3
of the weight to protect the same surface area. So if you are in high salinity environments with low pollution (pollution,low salinity can cause aluminum
anodes to passivate), we recommend using aluminum anodes. *

  • Brackish Water 

Zinc or magnesium is often used in brackish water. Preferably magnesium if you are not sure about the salt content. Brackish water is often more complex
to determine suitable anodes in, due to its fluctuations in resistivity, pH and bacteria (to name a few) more detailed measurements should be
done before deciding which anodes to use *


  • Fresh water

Due to its strong ability not to passivate and high driving voltage. Magnesium anodes are perfect for environments where there is high resistivity (low salinity) electrolyte present. Corrosion levels in fresh water are often less severe than high salt environments, but this does not mean that cathodic protection is not needed. For freshwater environments we recommend magnesium anodes *