Mills Basis A&B — Bioavailable Base NutrientMills Basis A&B Bioavailable Base Nutrient Not all base nutrients are created equal. Mills Basis A&B uses top quality raw ingredients with a specific focus on bioavailability meaning your plants actually absorb what you're feeding them, rather than leaving it locked in the reservoir. A favourite of serious growers who've tried everything and settled on Mills for consistency. Why growers choose Mills Basis A&B: Bioavailability focused formulation