Don't feed freeze-dried foods; they can lead to constipation.
Shrimp, squid, fish filets, Massivore, Algae Wafers are a good, varied diet. Just break or chop up the food into small enough pieces. He'll also eat earthworms at this size.
Don't expect the red tail to really develop for a couple of months yet.
Be sure that you're ready to accommodate his needs. He'll reach two feet in the year. If you have any questions about this, use the search tool. Feel free to PM me.