Leafs are pale green with brown spots on

Cal-Mag when watering and feeding. It won’t burn your ladies and is a cheap fix. Second thought: Manganese ( not magnesium) Manganese causes lighting of leaves and if not caught, dark spots that you are showing on the leaves …my only hesitation on manganese is that it is an immobile nutrient. Immobile nutrients show on younger leaves because it can’t be pulled from older leaves. I say cal-mag first because I see that your stalks are also purple. This could be cold, but cal-mag won’t burn your lady and is a simple fix and will help Not an exact science, but the plant gives insight by us reading the leaves of the plant.