purple leaves and stems

just had a plant do the same its a P/k deficiency. plants tend to show purple veins on stalk and purpling like burns on leaves when P is deficient it also has drying of edges like a K deficiency so i would assume its deficient in both P/k. mine fixed it by adding some Canna pk13/14. Had a look thru your diary that plant started going deficient from week 4 it started yellowing and burning. weeks 3-6 are where it will need the most and is where many think they are over feeding but in reality they are staring them. as sad from what i see i would up my pk boosters a the purpling stalks always indicate a P def unless its genetics,