I am starting up a colony of frontosas, and am in the process of acquiring them. I have about 4 little guys I just bought, between 1 and 2". I got them all for a really good deal, but in return they all seemed a little malnourished. All but one had a sunken belly, and the one who didn't have a cave belly had a flat belly. I stuck these four in a 29 for two weeks, and put them on a strict good food, clean water regimen. Three of the four have been eating like little pigs, and are already full bellied and getting color quickly (especially in the fins). They have also visibly grown, around a 1/4-1/2" each. One guy, however, has chosen to remain sunken bellied, and small. He does not exhibit odd behaviors, and constantly plays with the other fronts, digs in the sand, and keeps his finnage high and colorful. The only thing that bothers me is his sunken belly. If anything, he seems otherwise even healthier than my other Fronts. What do you think it might be? What do you suggest feeding him?