Bio load for me is no issue since i do WC twice a week, as for aggressive eater its fine aslong as they dont get on my polys way. Plus i like how they are peacefull that they dont reall bother my bichirs in the bottom. I feed the SD during morning with floating pellets and lettuce while at night i feed my bichirs during the lights are off.You can tell that they are related to piranha when it comes feeding time. They are voracious feeders and come feeding time there was no way I would get away without getting hosed when they went for the food. Otherwise they were just really stupid. They would be in a corner and freak out like they couldn't find their way out, lol, sad but true. Plus the bioload of seven large red hooks was trmendous. The tank maintence became so much easier when they were gone.