Every time I change Bob's water he sulks. He sits at the bottom of the tank doing nothing. When I did water changes on Sunday, he sulked at the bottom for the entire day and night. He ignored everything, food, stimulation, etc. The next day he was back to his old self.
He is in a 2.25G tank that gets 100% water changes every week. It is neither filtered nor heated. As long as you are diligent a filter is not needed IMO. As for how he is acting right now, I would give it a day and see how he is. Does he have any kind of plants or hidey holes in his tank? He is probably just scared from the move.