Ahh , "the talk"
Dog food is
the subject around my house these days. Some days I feel like its all I talk about so I know exactly how you feel. Mine started out on Science diet and beneful

I didn't know that their diet could be the cause of their problems with weight gain , itching etc. I am glad I found this site I just wish it was as easy as
1. Finding a great food
2.Putting your furbabies on it
3.They love it and everyone is happy

....
.....BUT It is not working that way for us

They either hate the food , or the food hates them ( lots of poo and tummy problems ) or I cant find the food locally.
It can be frustrating and I know you probably don't want to keep switching , especially during potty training , but the right food will probably help with that also ( less poo) so don't give up.
I know their are many brands and not all brands work for all dogs , so just keep at it

keep all the opinions in mind and just pick a place to start and go from there.