The isolation tank in fish tycoon is that little box that, when you put your fish in it, will show its age, what type of fish, health, and if its fed.

on the absolutely fabulous episode 'iso tank' when she gets out of the isolation tank she has a tattoo on her back and thigh so I think she does

it's an isolation tank for when they molt. they need peace and quiet here or else they will die, and the other crabs will eat them in the normal cage

Replace the fill valve or throttle down the isolation valve

Green section, Table of Initial Isolation and Protective Action Distances.