Your leaf damage appears to be from low nitrogen. The purple stems are most likely either a calcium and magnesium deficiency. You may want to give your plant 5 millilitres or 1 teaspoon per gallon of Grow Big to compensate for the low nitrogen in flowering. The lower leaves yellowing is normal during flowering due to low nitrogen.
Here is a link to the FoxFarm nutrient feeding schedules
Here is a link to the FoxFarm nutrient feeding schedules
Feeding Schedules - FoxFarm Soil & Fertilizer Company
Choose the feeding schedule that’s right for your growing needs. English (Imperial) Espanol (Metric) English & Espanol (Imperial and Metric) Tiếng Việt (METRIC) Hmoob (Metric)
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