I have had my Discus for 3 years and when we saw him in the pet shop he lookee magnificant so we purchased him my first Discus he lived in his tank until he started to grow then i decided to get him a bigger tank and some tank buddies, i thought he was happy showing all his colours which are red, blue, cream body with black stripes and red eyes. but lately he just won't show his colours and stays at the back of the tank, i keep a well maintained tank and i just can't think what i am doing wrong please help.