Hi Thanks for the sympathy all. I have reintroduced the offending barb. It is chasing the other, but no sign of fin nipping. I am going on holiday on Saturday, I think it's unfair to put new fish in with a friend in charge, so I figure the best option is to leave well alone for now. Just a thought - the nipped barb is looking very, very fat could she be about to spawn - is that why the other is bothering her? cool_jool