I recently picked up a 5-5.5 inch CK and placed him into the tank with a 3.5-4 inch Tiger Oscar. I figured he would be ok since there was no way he would fit in the Oscars mouth but I think the Oscar has been nipping at his fins. Should I grow the CK and my BGK out a little bit before adding any other tank mates? I'll probably try and sell the oscar to a lfs for store credit. Hopefully, I can get $5 for him considering they'll sell him for $15. Why am I guessing they'll refuse to buy him but take him for free