Bloom is a phosphorus heavy formula for enhancing flower production, as well as to encourage a plant to shift it's hormonal signals from vegetative to flowering. Bloom also contains potassium to enhance the plant's photosynthetic rate and energy transfer throughout the plant. Bloom also contains lower amounts of magnesium and sulfur, to help satisfy a plant's needs. Some sizes may not be stocked in all locations. Item will not ship UPS. Must ship on a pallet flat rate only.