He is gorgeous ... !!!!
At six months you can probably consider putting him on the Fromm 4* range ... it's actually an all-stages food suitable for any age of dog from puppy to senior.
The 4* range is really very well liked by a LOT of us on here .... and you can transition from Fromm Puppy to the 4* very quickly ... a matter of a few days.
Our new baby, Linus, is 14 weeks and is doing very well on the Fromm!!