I picked up a betta about 3 weeks ago from petco. I placed him in a non cycled 5 gallon aquarium, heated to 79 degrees. He ate the first 3-4 days, but has since went on a hunger strike for last 2.5 weeks. He also has cut back on his swimming and spends a lot of time sitting on the bottom. Honestly I wasn't worries too much about this but it has gone on for a long time now. I have tried betta pellets and frozen blood worms without success.
Originally, this struck me as maybe ammonia poisoning, but I have been vigilantly watching ammonia levels and doing regular water changes (using dechlorinated water). About a week ago, thinking maybe something toxic got into the tank during setup I moved him to approximately 1.5 gallon bowl that is getting daily 100% water changes and added aquarium salt. He still hasn't eaten anything, but yesterday produced a nice large bubblenest
. I have pulled out a flashlight and magnifying glass and see no visible sign of infection.
Is there anything else I can do for him? Is there any broad based medications that might be worth a shot? Just how long can he last without food?