Hi and welcome. I use Roudybush California blend. It is the first pellet all my fids would eat. I get it in mini. With the harness, make sure you check for wear and tear often. Even though they say it can't be chewed through, I have two that say otherwise. LOL My Sun Conure did them in.
I also have a TAG, he is eight years old. I say he, but we have not had him DNAed.