tail nipping

I had a small tail nipping problem in my 55 gallon and figured it was my skunk loach because they are known for agression and fin nipping, but i got rid of him a few days ago and it seems worse... As of now I have: 2 white skirts A 1 inch EBJD A 3 inch Blue Acara 3 clown loaches 3 corey cats 1...