I got a school of 2-3" Myleus schomburgkii black belt silver dollars on October 8th. They don't seem to have grown much if at all - still around 2-3". They're growing out in a 40 breeder. I feed them twice a day - spirulina flakes in the morning, spirulina + vibra bites or Xtreme aquatic nano pellets in the evening (for the sake of their young Heros severus buddy), about as much as they can eat in a minute. Are these guys just slow growers or does it sound like something is wrong?