Hydro A & B is a highly concentrated mineral-based plant nutrition for use during the plant’s growth and flowering phases. It contains all trace elements in a quickly absorbable (chelated) form. Hydro A is rich in calcium, which helps the plant resist heat stress. Hydro B contains magnesium, which enhances the production of chlorophyll, making it an indispensable building material that enables the plant to grow. Hydro A & B complement each other, resulting in a complete combination of nutrients. Hydro A & B can be used on all types of inert substrates.