So I have 8 guppies and 6 white skirt tetras in a 55g. I have had issues with fin nipping since I got them 6 months or so ago. I just moved them from a 20 tall to the 55g a month or so ago, hoping that more room would help, but it has not. Is there anything I can do to help stop this without getting a 3rd tank to keep the white skirts in?(have a gold fish in the 20)