What happens when you drain the aquarium?

[Shiny Umbreon]

I finally managed to drain it, but aside from the fish being gone, I cant find anything different. Did I mess something up?

[Erico]

Did you find that the decorations in the aquarium correspond to some of the features of the room?
And the X marks

[Shiny Umbreon]

Originally posted by Erico:

Did you find that the decorations in the aquarium correspond to some of the features of the room?
And the X marks

I found the X mark in front of the grill at the patio, the X mark at the laundromat, and the arrow pointing in the archive. Did I miss anything?

[Doombringer]

Those are the clues.
Aside from that draining the aquarium doesn't do anything else.

[Scrib]

Do the fish come back if you refill the aquarium?

[Doombringer]

yes