Black spot/clusters on upper leaves (PICS)

Running a ebb-and-flo hydroponic system, 3 weeks into flowering. The bottom leaves look fine, but the top ones are getting these clusters of black/brown dots. PH is at 6.3-6.5 and I'm using CNS17 RIPE at 25ml/4 liter.

Searched and searched and got very little except for a Manganese deficiency. Any thoughts?

i know this was a couple months ago, but that looks like cal mag deficiency, I had a really bad deficiency due to ph lockout with my super lemon haze... hopefully you fixed this by now

Yep that's a pretty late stage cal/mag deficiency. You can fix it but those yellow spotted leaves have been irreversibly damaged. Hope everything works out man! Namaste.

i think that's actually manganese, in which case more magnesium will make the problem worse

monkeybones said:

i think that's actually manganese, in which case more magnesium will make the problem worse

Click to expand...

Nope that's a cal/mag deficiency in its late stages. Seen it a million times lol. Namaste!

yea thats definitely cal mag... manganese would be bigger, darker and blacker spots