mine are too but my cichlids are very active and kicking up alot of sand. one side of my 55 has about half an inch of sand and the other has about 8 inches of sand and in a couple months that will change as they dig and move it to the other side of the tank lol. and then in my 30 with my sunfish he is just a jerk. he is constantly attacking his reflection and splashing water out of the tank as well as stirring up clouds of sand. but maybe i'm just lucky like that lol.