if your running PH perfect, why are you soo adiment on ppm's and PH. I am running the same shit right now, the entire 1liter grandmaster lineup from advanced. I refuse to use their microbials though, I think they suck and cause problems. I would rather add tea instead. I have a 6 in 1 meter similar like yours, only mine has ATC,PH,PPM,EC,CF. I do have it in the epicenter, however it's just a reference to values and makes it a tab bit easier to monitor plants. But with advanced nutrients I have found not to believe what the ppm's read. The buffers, aminos, b vits, chelators,all these have a value too and your reading that on the meter. Basically I read my plants, meter and water level. average all 3 into ventilaton,temp and RH. That's what tell me how much to push. if SHE STARTS TO BURN, THEN JUST INCREASE RH. or spay with water/b-52/superthrive/seltzer