I recently purchased some Satanoperca liliths. Some had slightly sunken bellies. Its been about a week and there bellies are still sunken. They are eating very aggressively but it seems like they sift out all the food. I feed nls .5mm and 1mm pellets. They look full width wise but I cant notice a bulge like I usually do in other cichlids. Should I be worried or just be patient and wait for them to fatten up? If so any idea on how long this might take?