I'm really struggling, I have a platy and a chubunkin goldfish in the same tank (was told that was okay) but the platy will not stop beating up the chubunkin, this is the third time he has had chunks out of his fins and just don't know what to do. I've tried separating them and they are okay after a while then fight again. I also tried adding more plants to creating hiding places but my platy will force the goldfish in to a corner and then charge at it....Is putting another chubunkin in a bad idea either to give mine a buddy or maybe another fish to take the load off. I have 28 litre tank :/