Wedding cake deficiency (coco)

[Humble]

Nutrients: Megacrop 5.5g/gal
Ph: was 6.3-6.4 for majority of grow until another grower told me to go to 5.8 because he believed it was a manganese deficiency (locks out at 6.0ph)
The brown necrotizing slowed down considerably but its still there. I noticed the issue starting at the bottom of the leaves. Then It started on top. Any help is appreciated.

 

[Cannabizz]

Calcium, Magnesium and Manganese should be implemented into your soil medium.

 

[NGA]

You use any cal-mag or Epson, your lighting led

 

[Thegermling]

You use any cal-mag or Epson, your lighting led

Calcium was like 96 ppm per gallon. I was supplementing 50ish ppms per gallon of mg via epsom (led) totaling around 74 ppm per gallon and I was told by another grower that my mg levels were to high and have since reduced it. The browning and mottling slowed down but its still there.

 

[dreamgreen]

what are you using for water? RO, distilled, tap...?

 

[Thegermling]

what are you using for water? RO, distilled, tap...?

My tap water registers 0ppm on my bluelab(700 scale).

 

[dreamgreen]

I was having similar problems using tap water. Turns out it was alkaline. Bought a distiller and all’s well. Yours may be fine though.