Things to know before using a freshwater tank for saltwater?

[cparka23]

I found a local ad for an ADA tank that had been used for a cichlid and am thinking about turning it into a nano reef. Before I snag it up, I'm wondering if there's anything I should know about using an old freshwater aquarium.

No copper-based meds, I know, but anything else?

 

[inactive]

Clean it like you were gonna eat out of it.