The Best Nutrients for Hydroponics

Hydroponic growing is different than growing vegetables and plants outdoors. Conditions in hydroponic growing must be carefully controlled to ensure that the plants get exactly what they need to grow quickly and productively. One critical input into the hydroponic growing process is nutrients. Plants growing outdoors can absorb nutrients through their roots from the surrounding soil. Hydroponic plants are grown in water and need to be provided with all of their nutritional needs artificially.

N-P-K Balanced Fertilizer

The three main nutrients required by all plants are nitrogen (N), phosphorus (P), and Potassium (K). Nitrogen is responsible for stem and leaf growth, phosphorus is important for root development and blooming, and potassium protects the plant from insects, diseases, and poor growing conditions. Hydroponic plants require a balanced fertilizer that contains all three nutrients, with the amount of nitrogen higher than the other two. A popular formulation for hydroponics is 20-10-10 which contains 20% nitrogen and 10% each of phosphorus and potassium. A fruiting plant would require more phosphorus relative to the nitrogen.

B Vitamin Supplement

B vitamins help the roots of hydroponic plants absorb other nutrients more effectively and increases the metabolism rate of the plants. This allows them to grow and produce more quickly- an important consideration in a hydroponic setup that requires electricity to operate.


Calcium is an important secondary nutrient that is required in leaves and stems to strengthen the cell walls. Hydroponic plants that lack calcium can show leaf burn- a blackening of the tips of new leaves, and other impacts such as blossom-end rot in hydroponic tomatoes. Calcium is often including in balanced N-P-K fertilizers but additional calcium may be required if the plants show symptoms of deficiency.


Sulphur is an important component in the photosynthesis process and leaves that lack sulphur are pale and gnarled. Sulphur is a common secondary nutrient included in many all-purpose hydroponic fertilizers but its uptake can be impeded by other ingredients. In these cases, additional sulphur should be added.


Magnesium is critical for light absorption in the leaves of hydroponic plants. Without enough of it, plants cannot create chlorophyll and will eventually die. Magnesium is rarely found separately outside of a balanced fertilizer.

Keywords: hydroponics, organic gardening, growing vegetables