the Cal in the Cal mag will not help the calcium toxicity that is causing his phosphorus lockout man.
from what I know about organic chemistry (very limited) the solution would be to lower the ph.... calcium is very alkaline, associated with high ph.
the high ph causes the lockout of other nutes, showing
signs of def's in the plant, even with heavy feeding; whereas the actual problem is more closely related to the high levels of calcium causing the medium to become more alkaline (higher ph), not an actual nutrient deficiency. lower the ph, the lockout goes away.... calcium by itself is relatively harmless to plants; but when dissolved by acidic water, it wreaks havoc on the ph over time. your hempy, flush the fuck out of those bitches, hit them with some 5.5-5.9 ph'd additive nutes after the flush.
at least thats what i would do. but i havent grown in hydro for almost 10 years, so take it with a grain of salt