fasting day

I was wondering why some people fast their bettas once a week or so... what are the benefits? At the moment I feed my bettas four pellets every day and don't fast at all, they seem to be doing fine. Should I start fasting them once a week?

My crowntail, Balthazar, is full of personality. I've had him now for almost a whole week, and already he recognizes me. I can tell because he gets excited and swims up to meet me when I approach the tank, but when my friend came over he swam away from him and hid in the corner. Anyway, today...