1st thank you for your service. As for your Betta, unfortunately, if it were me I would rehome him if I couldn't find some to care for him. 9 wks is going to be too long without a water change even with a filter, the water quality would be atrocious not to mention the evaporation after 9 wks. The auto feeders cannot be trusted from what I understand, many people have had them fail causing major water quality issues, fish over eating & having health issues. I hope you can find someone to care for him in your absence.