I have been raising clowns for awhile now and with lots of hard work and questions, I am slowly becoming more successful at raising babies to the juvenile stage. I have noticed that in a few of the batches of fry I have had, the majority of the babies will swim nose first against the tank walls. I have black mac tac on the sides of the tank, temp. is 81, salinity is o.018. I have tried subduing and brightening light above the tank, changed the amount of aeration (I use a rubber 10 inch airstone), added more rotifers, added or removed greenwater, and gently brushed the fry from the walls of the tank to no avail. I don't know if this behavior is normal or if it affects the survival rate of the fry. I am curious to know what causes this and any advice would be appreciated.