hi everyone, please reply to this and help me. i have had a female fancy guppy for a month and a half, and i have had a female gold platy for a month. i did a water change today (50%). i don't know if this effects my fish's behavior or not. my platy is hiding behind the filter and my guppy keeps coming up and biting her head. she tries to be aggressive and bites back. this has happened once before but they seemed to have solved it. my platy is not looking well. i'm sure she isn't pregnant, and the water is good quality. please help!!