ENtire PLant yellowing.....?

Ok Im in 15 gallon smart pots, in subcools super soil, and im in 2nd week of flowering, but lately my leaves have been yellowing on my two fire headbands... im sorry i cant get a well enough picture under the HPS... but the yellowing of leaves is wierd to me....its all over slightly, but the theirs random solid yellow leaves kindof all over the plants. vegged for 12weeks, RO water, ive been adding HALF the recommended dose of sensical , and ph'd 7.0

Early nitrogen deficiency perhaps.

I was thinking i may feed sensi cal half strength again, and half strength BUddha Bloom by roots organic......?! Hmmmm i wish i could post a picture

check the ph to make sure lockout is not happening sounds like the plant is not taking up Nitrogen. Is it really yellow or pale white? take a pic in natural lighting not he hps to show the true color

I could possibly drop the ph to 6.5? the run off has been steady at 6.5 , 6.6!!

This is the best i can do for now in regards to a picture, sorry if it doesnt help much

and no not pale white at all, just light green and yellow