I would like to make a pond for one of my rainbowsharks. I have two and I'll have to move one soon. I don't want to get a big new tanks for him. Could I put him in a plastic tub, like for moving and that. I've heard that it doesn't work that bad, and I want to do it indors. Since it is a warm water fish, would I need to put a heater in it? How would you make it into an indor pond?