Thanks. The thing that makes a picture like this hard are exposure for both the water and the people. The water has artificial light mixed with sunlight, and then filtered by many feet of water. Combined with an almost pitch black viewing room, and it makes for one heck of a tough shot with a lens only capable of going to f2.4.
Anyway, a little post process tweaking got what I wanted, which was a seamingly moody picture which showed good color pop, yet retained it's dark area shadow detail, and combined the ability to see both the aquarium inhabitants and the people equally well.
Sorry for the long winded reply, and thanks again for the comments.