Besides Titanium, what metal is suitable?

[GodFather]

Besides titanium, what metal is suitable for a marine aquarium environment? What should be avoided at all cost? Thanks.

[lightningstrike]

copper should be avoided at all cost.

[dradttg]

I think aluminium is good. I have been using it for my DIY and it has not rust at all.

Stainless Steel should be good too but make sure you get the top quality ones. Lousy ones will rust very fast.

[GodFather]

Just to give more background to my query. I am collaborating with an engineer/hobbyist to test the effect of a 150W peltier device. Our prototype is to submerge or have water pass across a heat exchanger. He has some titanium pipes in shipment for another project but wanted to test with others (perhaps cheaper options)

[Cookiemunster]

Just to give more background to my query. I am collaborating with an engineer/hobbyist to test the effect of a 150W peltier device. Our prototype is to submerge or have water pass across a heat exchanger. He has some titanium pipes in shipment for another project but wanted to test with others (perhaps cheaper options)

I was contemplating building such a device too. Already found all the materials needed. But only problem is the part that gets in contact with the marine water.

Aluminium cannot be used as it will corrode and produce aluminium oxide which is toxic to corals.

Titanium seems to be the only option but has poor thermal conductivity especially when its used as a heat conductor via peltier.

The way the commercial unit does it is to mould a metal rod which is coated. I am thinking of fabricating one too but did not have time to proceed.