I added four red tailed tinfoil barbs, and imo they seem to be more of a hinderance then anything. They don't give my GATF's a chance to get to the food, who are already very picky eaters, they only accept blood worms easily which doesn't fill them up. They have to compete with the barbs which are less shy to eat anything. Any advice?
That's typical. The barbs will feed voraciously and get the ATF's attention. Eventually the ATF will get hungry and attempt to get food from the barbs. He'll fail. After a while of failing, he'll begin to feed as aggressively as the barbs. It normally takes 2-3 weeks.