howdy Rob,
it's hard to tell what you need without knowing more on how the tree is planted.
is it in a bonsai pot with gravel soil or is it in a nursery pot and filled with dirt?Can you show pics?
typical bonsai soil does not have alot of organics in the soil so the tree must be fed with the fertalizer.the hard fert pellets are slow release and it will disolve into the soil in a few months.the liquid stuff is for a quick shot.