I have a 10 gallon fish tank and I had 2 guppies, 2 zebra danios, 1 platy, 1 gourami, and 1 molly. Back on September 30th I got a glofish tetra, another guppy, another platy, and a mystery snail. Everything seemed ok until two days ago. One of my guppies tails was completely shredded and...