if that is in my case, i would just leave it as is, and do the usual process that made it root. In my belief changing the routine, can stress the plant a bit, and if it does not like it, it will definitely go down the fertilizer bin.
In my experience, Phalaenopsis grow slow, and picky with its environment Condition.
Be patient.
By the way, i also have superthrive. I use it also on all my plants. (Misting, soaking, spraying, and watering)