So how old do they have to be to actually start forming pairs? Back when there were three angels in the tank, the current living one would often chase the other two and nip at them...but most of the time it'd leave the others alone. Yes, I put the salt in to treat disease, cuz i introduced a couple of unquarantined fish into the tank, which died shortly after...I was actually afraid that they would introduce some disease, so i put in salt