I'm 4 weeks into bloom. What ppm are your nutes at? Are you running DTW?
RDWC is what I ran with that. Also had an automatic PH adjustment so the pH flunctuations would stay in check.
I ran mine at around 700-800. Usually around 1000ppm I'd get leaf burn from it being too hot for the plants.
I always ran an early bloom and late bloom in conjunction
I always had to run extra CalMag with my water. When I started using some LEDs i pretty much had to run it on every strain. The chem 4 is a CalMag whore so some strains need it more than others.
Also I did cut back on the nitrate and just used the CalMag as a replacement for the straight calcium nitrate. Used a base of around 180 ppm and then added in the Jack's. If I still got some purpling then next feeding I would increase the CalMag some more. CalMag is pretty much calcium nitrate and Epsom salt (magnesium).
In my boosters I would add at 3 ml per gal. Seemed to me that if I really tried to push a plant the more it was likely to go out of whack. That's why I never liked going over 800 ppm. Autoflowers really dislike higher ppms.
I just did a rez change and trying some megacrop again. Both in veg and flower. The PH wants to fall all the time with it.