Feeders have to be gut loaded with good food in order for the fish consuming them to get nutritional benefits. Read up on bio accumulation to understand the whole idea. Since your quarantining the feeders I would be OK with that as your not getting them directly from the store and dropping them in the tank. I just don't feed feeders as I never wanted my gars to get attached to them as they were raised on fillet and pellets. In order to hand feed the gar needs to become comfortable with the one feeding it. At its current size just leave feeders in the tank so he can eat when he wants. Try to get him off feeders when he gets comfortable with the tank, I just dropped fillet into the tank and by the next mourning it was gone. Adventually I had him eating fillet off a shishcabob (spelling?) toothpick that was held by hand and then finally hand feeding
