I am kicking myself for this. I came home to one less betta today. And It is my fault. I decided to put some neon tetras into the biggest part of my separated 20 long and everything seemed to be fine for the month that they have been in there. Until I came home today to find Newt dead. I can only guess as to what happened but it looks like the tetras bullied him to death, there was absolutely nothing left of any of his fins and probably couldn't get to the surface to get air. I am so sorry my little pink man...