Hydro A&B is a highly concentrated mineral basic plant food for use during the plant’s growth and flowering phase. Hydro A is rich in calcium which helps the plant against heat stress. Hydro B contains magnesium which enhances the production of chlorophyll, making it an indispensable building material enabling 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.