I used to have BIG parrot fish called dave, and he was a little fucker too!! If you stuck your finger in the water he'd aim straight for it and 'latch' on to it!! he bullied EVERYTHING! But, as soon as i put a plec in, he tried to bully him, but after finding out he wasnt that bothered he gave up!!

he was sound after that!

have you tried feeding them bloodworms?