Aluminum Refugium is it safe?

[windcoast reefs]

I would avoid it all together, just go and get a cheap used tank or a rubber made.

If you are using an alloy and even to an extent pure (ish) aluminum, it can contain copper, zinc, manganese, and a whole host of other element.

[hillegom]

Al corrodes in saltwater. Thats why al fish boats and lower legs from outboards have a zinc piece bolted to them. It becomes the sacrificial anode and corrodes first. You don't want zinc in your tank either