I have just become the proud owner of a 15 week old GSD 
He is currently on Beart's Old Peter Value nibble but I'm not sure if this suits him as he has very sloppy poos! I want to change him onto a better food but I'm not sure if something like the Royal Canin GS Puppy is a good brand (despite it being recommended by vet/trainer) as I have read mixed reviews online.
I like the sound of the Skinner's puppy food, either field and trial or lamb and rice, and if I'm honest these would fit better within our family budget.
It's so difficult because some of the 'better' brands say you need to feed less of them so how do I work out what is best for my puppy and my budget? If you've read this far and have got any ideas that would be great, thanks 