Do you mean add a filter to the dish? I don't have one because I change water often plus I don't want any objects taking up space. I already have 3 smooth rocks piled in a way to support one end of a driftwood log, the other end is on land. Oh, mine move but then again sit for periods at a time. And I would not add another creature unless it would be safe. FB's seem happy, just bored. I sure do miss having a turtle like I did when I was a kid, it was my favorite pet besides a dog! So, that means a newt is out, plus any other little reptile. Hmmm, does that leave anything?