Gramma attacking firefish

[craiguk]

After 1 year of living peacefully together, my royal gramma has started being aggressive towards my firefish.

Been going on 3 days. Last fish I added was a wrasse (2 weeks ago), to replace one I unfortunately lost (first fish loss :-( he'd beenhappy for 8 months). No signs of disease. Left it 4 weeks before replacing to be sure. Everything else fine. Params good and stable. 500L tank, plenty of places to hide. Not too much stock.

Any ideas on change in behaviour? Anything I can do?

 

[blaxsun]

You can try the "mirror trick" by hanging a small mirror on the side of the tank. It may work to distract either fish. I've had some success but of course YMMV.