So I have had 5 exodons in a 24" X 18" X 18" tank for about 3 weeks or so. Yesterday i found on Exodon at a LFS in a tank full of baby red's. I bought said fish and put him in with the 5 others I have. Everything seemed fine lastnight when I left for work. Today i come home to find the new fish hiding behind the heater and looks to be picked apart on his sides pretty badly. The new fish is the largest of the 6 in the tank...... Any ideas? Is it not a good idea to mix them?