Beautiful stuff, the inside feels like the UI of a videogame I'd jump to try out.
I wasn't entirely sure how the movement process worked. If it takes 6 hours to go from one stage to the next and the tanks last 12 hours you need to solve each tier in order, which goes a it against the freedom that water invokes. But maybe I missunderstood.
If you ever come back to this, please consider adding a Theta-2 intoxication progression because I'm sure players will try to eat the fish no matter how contaminated or agressive the warden makes them look.