My senegals LOVED krill, ravenously devouring any and all bits (whole or partial) in their grow-out. Now that they're in a 55, they won't touch it. My ornate ignores krill, and the only fish that pick at it are rosy barbs (in with the sens). I stopped even trying - it's silversides, sinking carnivore pellets, and blood/blackworms now.