Okay, I know saying my Clowns are acting strange is kind of like saying "my cat sleeps a lot". But anyway, they are constantly rubbing up against rocks and twitching like something is irritating them. They have no spots, are eating fine, are not swimming with their pectoral fins held in and besides the rubbing and twitching seem fine. Nothing has changed in the tank for the past two weeks and besides being a little low on calcium (400) my water parameters are all fine. Any ideas anyone?