Cal mag or Manganese and possible solutions?

Not quite sure what to do with this. I did some research but i am scratching my head on this one.

I have a pretty simple setup. I use foxfarm ocean forest with about 30 grams worth of grow dots mixed into the soil at the time of transfer into a 3gal pot. Watering PH started at between 6.5-7.0, This spotting started predominantly when heavy into flowering. All my research pointed to a manganese deficiency so i ended up flushing the plant at 6.0 and diluting some manganese sulfate into 6.0 water...about 15grams worth for a gallon of 6.0 water. I also follier fed with same water/mang solution to see if it helped. I also ended up snipping the heavily damaged leaves but doesn't seem to be slowing down. Any ideas would be great.