Anyone know what's causing this? Slight discoloration and rust spots, mainly on older leaves. It's not that bad but quite spread out. did spray with neem oil recently, so is it just burn spots or a nutrient problem?
I there iv not used your range of nutrient for a while, have you got the right ratios of nitrogen phosphorus potassium Calcium and magnesium. Check out a feed schedule for your product and make sure your giving enough Calcium ànd magnesium. If a max dose is 2ml/L you shouldn't need to go above that.