Mandarin Cookies

Entering weeks 9 of flowering (56days since light switch) Might be last weeks for them except Purple sunset still has one week to go. Starting to flush next week. A lot of brown, mottling spots still do not know why. I guess humidity too low (sometimes drop to 35 and swing around 35-55). Feeding🌱💦 9/1 water13L +fulltilt15g+budcandy 26ml +calmag 15ml+purpinator 12ml ph6 ppm750 21:14 temp 22 rh45 11/1 52days from light switch. Plain water ph6-6.3 ppm15 2L per pots. 2.7 for Mandarin 13/1 Water+5ml calmag ppm55 ph5.9-6.2 2L per pot. Mdr3L Any advice you can leave in a comment. I really appreciate all of your like and comments it’s make me feel like I’m still live in this world. I have a question for next weeks - What recommended ph for flushing ( I use flawless finish Advanced nutrient) - Any secret method for the last week. - Should I add calmag with flushing?