Zinc or aluminium anodes dilemma

[SmoothieSwt]

Alright, my buddy Brad is in a pickle with his Jeanneau Sun Odyssey 410 sailboat over in the west coast.
He's been told to swap his zinc anodes for aluminum since aluminum works better in that low salinity water.

The problem? Most folks say you shouldn't mix them, but the Vetus bow thruster only comes with a zinc anode, and Vetus themselves told him mixing is fine! He's stumped on who's right, especially since he can't check if the thruster is electrically isolated.

He's also trying to find out how many anodes are actually on his boat. He knows about the prop, hull, and bow thruster ones, but wonders if the Yanmar 3JH4E engine or hot water cylinder have any.

Any advice for Brad would be awesome!

 

[AyJay22]

Honestly, if he cant confirm that the thruster is properly isolated, he's gambling with the gear, he should check the continuity with a multimeter nd yeah you can mix anodes in theory if everything id isolated but in practice, you've got to really know your boat inside out
Yanmar usually has a pencil anode near the heat exchanger, and depending on the setup, the water heater might too, look for manuals I guess

 

[Roger dat]

Mixing zinc and aluminum is usually a no go when everything is electrically connected but if the Vetus thruster is isolated like they say, then the zinc won't mess with the aluminum anodes elsewhere, I like what @AyJay22 has said and I agree, by the way in low salinity water, switching to all aluminum is smart if he can make it work

 

[Eaglet_Jim]

Is Brad able to confirm whether the bow thruster is electrically isolated? That'll determine if mixing zinc and aluminum anodes is safe, and has he checked the engine and hot water cylinder for extra anodes?