Hmm alright, I don't use fish store feeders, I've been using my own guppiesReally you should keep as many feeder as you can with him, gar need constant supply of food in their first year of growth. You wont overfeed him. Just beware of the risk in the retail sources of your feeders(parasites) and also the size of the feeders.
Also check out the stickies on somatic growth and other growth information, there is gold in there i swear lol.