I'm lucky enough to have a nearby hydroponics store which sells the fertilizer I like. I'm currently using Dynagrow, and have had excellent results. When that is gone I have a bottle of MSU I bought from Ray that I want to try. In fact I think Ray sells both on his website. I'm a little scared of using a high nitrogen fert. It's way too easy to burn the plants. I'm feeding at about 100-125 ppm once a week during the growing season, and that seems to be working well for me. I just spotted a Lc. on my shelf that it spiking.
I think your Phal will be fine. As has already been said they sometimes need a nap after being stressed. It will eventually snap out of it and before you know it you'll see a little green leaf tip sticking up out of the middle. That should shortly be accompanied by new root growth.