I have 2 jack dempseys in 1, 55 gal tank. The larger jack is roughly 4 inches the smaller jack is about 2.5-3 inches. When I first got the pair they were only about a .5 inch(or less) difference. I suspect the pair to be both male due to the fact the larger jack chases the smaller one around alot. I never see any signs of aggression beyond that. Also my jacks don't eat hikari pellets but everything else(flakes, brine, bloods, shrimp pels, live fish, new spectrum pels). I'm considering getting rid of my smaller jack due to the fact that I feel like the reason he's staying so small is because he isn't getting enough to eat and would hate for him to eventually die at the hands of the larger jack. Any ideas why he's growing so slow? Any ideas why they won't eat hikari pellets?