I've noticed a change in my JBP. The needles have mottled light green through out. I tried Google and the closest thing is ozone damage which is improbable. Could it be needle cast ? Water pH?
Any ideas? Deficiency of some sort?
I think you're right with the needle cast. But I haven't seen it this severe and I personally don't want to put you on the wrong track. It could be something else that I've never seen.
Did you check out the resource made by Bohne? https://www.bonsainut.com/resources/flow-chart-for-diagnosis-pine-problems.24/
If you can rule out or rule in root issues, that would help the diagnosis.