Personally I think "A," and giving a greater impression of depth, is a great idea: part of the reason I like the aquarium so much is the impression it gives of displaying a tiny window into a much larger world. Makes it that much less claustrophobic, which is a problem SimAquarium (for example) can have with that surface and too many fish. (That's why Jim not having tank sides or a water surface and only 7 (or 8) fish bothers me not one tiny jot!
)
P.S. Many apologies to /Tiny!