I have a 20g tank with 7 bloodfin tetras, 3 dwarf rainbow fish and 6 cories. My tank is cycled and has been set up since April. Most of these fish have been with me since the beginning. As of last week, the tetras have stopped eating the flakes (they put them in their mouths and spit them out). I was using aqueon tropical flake but after reading some reviews on this site, I recently purchased omega one flakes hoping they would enjoy new flakes, however the same behavior is happening here. The tetras will eat at the shrimp pellets I put in the tank for the cories. I find it strange that one day they stopped eating the flakes all together. Has this happened to anyone else? Is the solution finding a different type of food they might enjoy?