I have raised 4 Arowanas in the past and every time I've noticed drop eye was right after they smashed the top of my lid. In fact, I actually watched one of my Arowanas smash the top of the lid and his eye immediately dropped. I was wondering.... is this why pond-raised Arowanas seem not to have this problem while tank-raised Arowanas do. It's just a theory, but I wanted to see if others have had this problem.