I have a 46G Cichlid Tank with:
Tiger Oscar (3 1/2")
Albino Tiger Oscar (3")
Jack Dempsey (2 1/2")
Blood Parrot (3")
Gold Gourami (2 1/2")
Green Terror (1 1/2")
For the most part, the last 3 months, all the fish have gotten along great. The only aggressive fish has been the Convict protecting his territory, but other than that all the fish have been great.
The last two days, however, the Tiger Oscar, Convict, and Jack Dempsey have started picking on the Albino Oscar. His fins were mildly torn and he has a few "bite" marks on his side. I put him in a small quarantine breeding tank within the 46G overnight to see if that would help. I fed the fish this morning and after he ate I let him go back into the tank. I went to the Camden Aquarium with my gf and when I got back about 6 hours later he was in the back of the tank kind of laying on his side.
I don't understand the sudden aggression towards one fish out of nowhere. Is there any explanation for this? Should I start cycling an empty 10G I have and put him in there alone?
I'm getting a 110G tank with 2 overflows, a sump, and everything else needed to set it up. That's the tank I want my Oscars to grow up in, just the 2 of them, but they need to get along!