Hi, I'm a new owner of a axolotl I only got him yesterday, but have a few questions, he seems calm & relaxed but i've noticed he'll head down towards the filter & flipps out (4ft tank), he goes alittle crazy, but he then calms down heads back towards the other end & seems relaxed again. He's eating, I feed him last night & he ate with no problems, Is this normal behaviour?? any advice please?