High EC and PH

Oh EC for that is around 1.7 good luck.

Your EC is way too high no mater the PH. the range in PPM you should be hitting with nutes If you are mixing solo should be 3-400ppm about 0.8EC if you are mixing a batch be sure to add micros and the PPM range should be 9-1400 at max and thats even high. Lower your EC to this or you'll have real trouble pal

The DE looks like that on the plant because that night at lights off I sprayed the leaves with plain water to try and wash the DE off but some stayed on and just kinda smeared like that

The white stuff is DE I accidently got on the leaves a couple weeks ago when I was sprinkling it on the medium. The feeding was .4 EC and run off was .7 EC. I was feeding so low to try and bring the EC down, earlier this week it was 1.0 and I saw some brown spots starting to form on some fan leaves so I thought I was overfeeding also the tips on the new growth had me concerned that it was nutrient burn.

Temperature is at 75-76 with humidity around 55%, night time 72-73 humidity 50%. I feed once per day till run off. Using the bloomgrow 600W LED which is really 100W I believe from the wall, currently 18-20" above the canopy I can't get it any higher than that, also have two fans, one on the bottom and one on the top, so I know I have good airflow. I've been using about half nutes for 2-3 feedings now and did a flush as well with plain ph balanced water and the symptoms are still getting worse.