First week of flower leaves yellow overnight

First off thanks to everyone who reads this. Whether you reply or not thanks for taking the time. I just flipped my ladies almost a week ago. I have them in 3 gal grow bags ocean forest with light warrior and extra perlite. There is only four at the moment in a 5x5 hydro hut under a 600 hps. I took readings of the run off which is usually a good indicator for me when to start adding my own nutes (usually when its drops to around 1200ppm) and they are still too high for my meter to read. I am very perplexed never had a problem like this before. I just flipped to 12/12 the nodes are already showing signs of buds but the top leaves and new growth is becoming completely yellow. I hope these pictures help.

additional info: No co2 temps/ 73 when light on around 70 when off 50 % humidity at the moment and good airflow also up until now i have added no extra nutes just phd ro water and calmag

I have looked through several diagnosing guides and nothing says anything about the yellowing starting at the top. They were under a t5 maybe the sudden hps shocked them i dont know. Pease help BUMP!!!!

i think you probably should have been feeding from the get-go. ffof does contain ferts. but not enough to warrant not feeding at all. i used bogs soil mix, and he used a reduced rate of pure blend. i believe it was 1 1/2 tbsp. per gallon. they're hungry, feed em!