DS2 has been on 4 hour EASY for a couple weeks now so he is down to 5 bottles including a DF. Can't drop the DF! He only drinks 20 oz - 4 oz in each bottle!! I can't figure out why or how to get him to drink more. He has been steadily gaining 2 lbs a month since birth and is at 15 lbs now. Just 20 oz doesn't seem like nearly enough! He's happy and all smiles. Sleeping good for naps and night. Has chubby thighs and cheeks so just by looking at him you wouldn't think he is drinking such a measly amount of milk. 20 oz! Help!