I have a 4' tank but its also 24" wide and 24" tall. Better suited for these fish than the 80 is. I personally wouldn't keep them in an 80. The 120 is the smallest I would go, I second the group of anthias. I had a trio of lyretails for 2 years, lost them when my tank cracked. I'm now going for Bartletts I think still not 100% on them though.