Welcome to the Meyer Lemon Tree club
. I got mine recently and I am pretty happy about it.
As you're in hardiness zone 6, I am assuming it will be spending the winters indoors, so yeah,
@Chuck makes a good point. Mine is in a 10 inch diameter pot at the moment. My tree is quite small, so I am not using anything to big at the moment.
I don't know much, but I do know that it needs a lot of direct sunlight and not to be over watered.
Fertilizers. Oh man, I have tried to find an answer to this and everyone says something different. I think the most popular NPK ratio that people have said is 3-1-2. Someone on this site recommended just using a organic fertilizer designed for roses. Either way, depending on the size of your tree will depend on how much you should fertilize it. Also, that same person suggested using Epsom salts.
Also, talking to it helps a lot
I'm still trying to learn about my tree, so I really don't know much, but I wanted to share the little I do know.