you should consider what kind of fish, or the personality. some fish like to explore tubes holes, etc. some dont. i know, for instance when my danios get spooked they swim up. corys swim down.
i used to keep an upside down glass in my aquarium for my danios to chase each other in and around. (danio playground equipment) but every once in a while one would get in there and freak out. one time the poor girl got so freaked out she threw up! i took the playground out after that. put a nice java fern instead.
i used to keep an upside down glass in my aquarium for my danios to chase each other in and around. (danio playground equipment) but every once in a while one would get in there and freak out. one time the poor girl got so freaked out she threw up! i took the playground out after that. put a nice java fern instead.