Aggressive A. Australe Killifish

I have a 10 gallon that was up until yesterday a species only CPD tank. It is moderately planted with lots of hiding places. I have 7 CPD’s and added a juvenile lyretail killifish yesterday. He is very active, been doing a little glass surfing, (I thinkbhe is seeing his reflection but could be wrong), but otherwise seemed okay. My water parameters are perfect 0/0/5. This morning I noticed many of the CPD’s tails were shredded and one seemed to have a damaged eye. This evening, when I turned the blue light on for an hour before bed I started seeing a lot if aggression and attacking from the Killifish. I know all fish are different but all of my research claimed this species of Killifish to be shy and timid and good for a community tamk IF he had similar tank
Ates. . Do you think he could be stressed and this could pass or do you think i “lucked” out with a meanie? I am setting up my hospital tank as I type this so i can remove him but wondered if any of you had any other thoughts/ideas.
Thanks!

 

Australes tend to be a more retiring killie, but that's always relative and CPDs are possibly too shy to keep with killies. If you want to try again, I'd suggest adding a couple of female australes along with him, which will hopefully give him something to focus on and remove the aggression from your CPDs.

 

Thank you!