I have 2 Blood Parrot fish. They are around 2 years old. I first had them together when young for about 6 months. As adults they began to fight badly. The 1 has a very big size difference. The smaller one was getting stressed and getting the black Mark's on him. Since around 1 year old, I believe these are 2 males. I tried all the common fixes for 3 months nothing worked. So I got a Craigslist deal on a separate tank and split them. This past year they have been doing good. They just always seemed happier together except the fighting. I put them back together again last night to see if they would be better now since the smaller one has grown to about the same size. Right away they were good together seemed to remember each other and swim together, livelier, rub against each other, and seemed happier. But today they started fighting again. Not as bad as before, but now the opposite, bigger one is starting with the other one. They only hit at lips sometimes now not full lip locking and shoving like they used to do. But still I separated them again to be cautious. I wonder why this is and if I get a bigger tank could they ever live together again as adults? And why are they doing this? Will they ever get along or will I just keep them separated forever?