OK thanks for the info, I think we can help now
first ProMix soil has no real nutes in it, does have Cal/Mag from the dolomite
and the Shultz is not a complete fert (only has 3 of the micronutes)
Not sure about the grandma stuff ?? Sorry but I'm not into the "secret formula" stuff
what you NEED with ProMix is a complete fert, I like DynaGro as it has everything a plant needs
Also I would not feed the shultz every watering and I would start the mend with a good flush then start feeding a complete food (or a mix that is complete) watch it for a few days looking for new healthy growth
Also when you water you need lots of runoff, I would also invite you to read my NooB Advice thread, (yeah it's long just read the 1st 40 pages)