Quite naturally, plant nutrients play a crucial role in water plant aquaristics in general and in aquascaping in particular. Without macro- and micronutrients, aquatic plants cannot grow. Macronutrients are carbon (C), oxygen (O), hydrogen (H), nitrogen (N), phosphate (P), potassium (K), sulphur (S), calcium (Ca) and magnesium (Mg). Plants need larger amounts of macronutrients than of micronutrients. Central macronutrients are nitrogen, phosphor and potassium. Nitrogen is added to planted tanks mainly in the form of nitrate, phosphor in the form of phosphate. Micronutrients are iron (Fe), chlorine (Cl), manganese (Mn), zinc (Zn), copper (Cu), boron (B), molybdenum (Mo), cobalt (Co) and nickel (Ni). Plants use a far lesser amount of these nutrients than of macronutrients. For this reason you only need to add small quantities of these to your tank.
However, if only one single element of this list of essential micro- and macronutrients is missing, aquatic plants will not grow. Thus, any planted tank or aquascape ought to be fertilised with a complete range of nutrients in order to safeguard optimal plant growth.