Marihuahnma The plant continues to grow well.
However, the brown spots are also appearing in the upper third.
Advanced Nutrients told me it wasn't necessary to adjust the pH, so the brown spots are probably the result.
Since this happens every time around week three of flowering, I suspect she isn't getting enough potassium.
The nutrient solution has a pH of about 6.3.
From today on, I will adjust the pH for all 4 plants again.
At least that way, we can rule out one mistake.
Great plant so far!