Don't know how small your talking, but with silvers I had the were 3-3.5" freeze dried blood worms a good. The freeze dried blood worms float, and are soft ideal for young aros. Also you can break up pelets into a very small peicies and feed with the blood worms, this will help with the aro aquaireing the taste for the pellets.
Once your aro eats eagerly you can go with frozen foods, as long as they are eaten before sinking to the bottom.