Hello, I have a 20gl tank with a decent amount of plants, one medium sized angelfish, and one BN pleco. I have had this setup for about a month now and it has had no problems. However recently, I decided that it could use another fish. I was thinking about maybe adding 1 Bolivian Ram to the stock. Will these fish be okay together? I know that they can both be territorial fish, and is it going to be a problem that the angelfish has already established it's territory? I want there to be absolutely no aggression in the tank. Also, I've heard that angelfish are normally only aggressive with other angels and fish that they can fit in their mouths. So theoretically, the ram should be fine. Is this true? Anyway, if anyone has any experience, let me know. Thanks.