Outstanding work Sir! I cannot tell what your airflow looks like in those shots but don't be afraid to set it at a good rate - as you know oxygen is critical for the fry and the rots - in large numbers it's easy for them to find themselves in a situation where they compete for the air. Keep a good eye on your rot count in the fry tank as well. With those numbers they should be depleting the rots population pretty quickly. And lat the first couple of hits with the OTO - don't expect them all to attack it. It will not be instinctual to them to hit it and they need to get used to it. I always feed a light dusting of OTO but do even less then I normally would the first few days. You are well on your way!!