How do I get on top of a phosphorus deficiency in ...

Stop using PK 13/14. Save this product for when your in the mid to end of bloom. Your part A/B should already have enough for your plants in veg. You definately have a PK excess. K blocks out magnesium. P blocks out iron, manganese,zinc or copper. It looks like you have either a magnesium or an iron deficiency or both. You can use Epsom salt(magnesium sulfate) as a foliage spray at 1 teaspoon per gallon add a few drops of baby shampoo as a surfactant. Spray every 4 or five days until she greens up again. Be sure to spray the underside of the leaves as best you can. Do this at lights out so the lights don't magnify the water drops leaving brown spots on the leaves. I she's not greening up you can do the same thing with an iron product or a product that contains iron. You may be able to use Epsom salt in your hydro solution but I don't know what the dose would be. Hope this greens your girls up good luck.