I've had a female betta fish for a year now. I have two other bettas and I usually clean the tanks every three weeks. I don't vacuum the gravel because my syphon won't start. my female betta suddenly began acting weird. She started darting around the cage. Now shes all scratched up and she began pailing. then she got fin rot. I moved her to an empty, smaller tank so she couldn't scratch herself anymore. I'm changing the water every couple of days now but she doesn't seem to get better. shes starting to worry me cause shes lying on her side at the bottom of the tank. I'm desperate what should I do? shes in a half gallon tank right now. what should I do?