Hi. I now have 4 guppies (2 male, 2 female), 4 platies (3 male, 1 female) and 1 chinese marble algae eater in my 20 gal tank. It has lots of plants and decorations. Everything was going along so well and lately I noticed my 2 female guppies hiding lots. I wasn't sure why but now I notice their fins are getting chewed up. I can't imagine who is doing it. When I had just guppies before I never had that problem. And the platies were supposed to be peaceful. I figured algae eaters were peaceful. The female guppies are quite small yet, maybe an inch long at the most so they are smaller compared to the platies. Any ideas?