how are the penguin and emeror filters as far as use for saltwater? they say on the box that they are OK for marine use, but would they be a realistic choise for use in a FOWLR? say I got two of the emperor 400 which is rated for 90gal tanks for a 110 aquarium? Would that along with a decent skimer be ok for say, 5-6 med size fish? (Tangs, lionfish, puffers, etc.)