Mirrored glass for sump?

[Rogue951]

so I went to speedy glass and asked for some partitions for my sump.
They cut me MIRRORED glass instead! (course I didn't look till I got home)
Is this safe to use in saltwater? do I have to worry about the coating?
now I kind of think it'd be cool to have the refugium part surrounded on the 2 sides by a mirror just so I can see around the rocks.
(dunno if my fish will like... )
if not I'll have to go back to them which is going to be inconvenient. the work order even says clear.

Thanks!!