For about a week now, my betta has purple velvety fins(and tail) but his head is a grayish color. Is this a health symptom ? If so , can you describe the cause,what it is, and how is it treated. Now today, i did a water change and i put him back in the tank after wards, put the conditioner in like always & he started to go down. he was lying on his side at the bottom. I stuck my finger in the tank, and held him against the glass as he swam. he then lied back down and was breathing fast but wouldn't go to the surface for oxygen. Please help, im worried.