Whiteish damage

This could be related to S-deficiency. it's on edge of purple... so it was already going downhill in regard to receiving light. Does not look like light burn based on what sorrounds it at same level. heh, kinda points toward trace elements, which is very unlikely in soil. Zn / Fe deficiencies. so, double check tht pH as before... if pH is fine, i'd lean toward this just being part of being a bit underfed + senescence. more about previous quetion -- if you do add some magnesium sulfate (foodgrade, doesn't even have to be a specific garden product), just go about 1g/gallon mixed.