I have had 2 pikes die on me. 1st 4" saxatilis. I had it for about 2 weeks. 2nd was orange pike. Same size. They were in a 90 with 2-2" peacock temensis, 1 6" silver arowana, 1 6" Lima shovelnose, 1 polypterus. They nth were doing great, eating great, and looks healthy. I just bought a apotapo II. I don't want to keep killing these little guys. My current pike is still looking great. Is there anything I should look for or check?