Gorilla Glue Auto and LSD-25 Auto

I'm noticing the leaves yellowing, especially on LSD-25. My coco and perlite mix is well mixed to allow for a good aeration, so I doubt it's overwatering. The light PAR reading on my phone is showing around 240-270 micro moles per m2 per second, which should be in the limit allowed. I know the phone can have inaccuracies since it is not an actual PAR sensor, but I don't think it is strong enough to cause light burn. The only thing I can think it might be is some kind of nutrient deficiency since I am really trying not to give my plants nutrient burn. I have been keeping EC relatively low, I am currently at 300 to 400 Micro Siemens and I am slowly increasing the salinity by 50-100 increments. I believe I should be coming closer to 1000 micro Siemens. Also, LSD-25's runoff EC is always significantly higher than Gorilla Glue's. To counteract this I fertigate LSD more, till the runoff EC starts to come closer to being within +200 Micro Siemens. Since the EC is high, could this mean she's actually getting nutrient burn? The pH is always measured and is always around 6.0-6.2 Any help would be appreciated, in the meantime I will try to keep increasing EC and keep a closer eye on LSD, while doing my own research on the topic. Thanks