Hi, I was wondering if you can help me. On Sunday (after setting up my tank and leaving it to cycle) I bought my first fish, 5 tiger barbs. I put them in, followed all the instructions and at first they were fine. Then I noticed that one of them became territorial over the central rock, chasing away any barb that came near it. I didn't think much of it until the next morning...when I saw that he was now chasing all the fish into the top right hand corner, not allowing them out. I left it to see if things calmed down...but it really got worse, he sometimes went up there just to chase them. So I decided maybe I didn't get a big enough shoal, so on the pet shops advice yesterday I added 5 more tiger barbs. Things were calm for only a while then he bullied all those fish aswell...and now all nine are kept in the right hand corner whilst he has the rest of the tank to himself. I've noticed he's calmer when the lights are off but no-one seems to be challeging him, there''s only been one fight and that was over very quickly. I'm very worried about my other 9 fish, what do you recommend?