Finish the Nutro Max...it will not hurt to keep puppy on it for a short time longer.
Nutro Max is the poorest in quality of all of the Nutro foods.
Take a look at the back of the bag...and tell us what the first 5 ingredients are. If I remember right it's very little meat and lots of corn.
Canidae ALS is an excellent food, you will have to feed less...it's got more meat and higher in calories.
Gina