Everyone worries about the con, lol. What about the del? Ive owned some pretty mean little convicts that took on much bigger fish. I had one that stripped the fins off multiple pleco tankmates. Dels can be pretty easy going and I could see this little con not liking where the del was sitting and nip at his fins and biting it constantly. I know its a 75g but still I trust the del more than the convict.