THANKSgood looking gar hopefully he becomes a monster one day! This is my monster in the making, his name is jerry GARcia and he is about 17 inchesView attachment 1349155
U could try starving it. If it ate only guppies it might not any other foods... so if u don't mind giving it live fish keep on giving it. But if u don't want to use live foods(like me) try to starve it for about 3-4 days or maybe even a week.
It'll start to eat. I feed mine small pieces of cut shrimp or raw fish.
How big is ur Gar?