its been a week since i had my rhomb, its in a 55g with 2 small 2 inch reds in there, but he hasn't eatin anything, i tried feediing him brine shrimp, and raw white fish filet, and he doesn't ever bother, im getting kind of worried, i know he's still new to the tank, but his stomach looks like its getting smaller and thinner and he looks hungry, but will not eat, the little reds however eat whenever i throw anything in the water, im hoping that he would take out one of my little reds. what should i do? should i be worried? the previous owner had him on pellet food for 5 years, you think that could be it? HELP!