I have a 30 gallon tank and recently bought a new angel. I have two now, and I believe that they are a male and female, although I'm not a hundred percent sure. I have recently noticed that the female (who is larger than the male) has frayed and nipped fins. The male also seems to have these. I have two rather small gold barbs (very peaceful) and three cory cats along with the angels. I do water changes every two weeks. I really want to know why they are doing this, as i don't want their beautiful fins to become damaged. Thanks in advance