Editor’s note
2/3/2026 — This new publication is currently only available as a PDF. The full text will be available on this webpage soon.
See the Hydroponic Nutrient Solutions Calculator (XLSX) for more information.
Nutrient solutions are a vital part of hydroponic crop care. Although production requirements can vary greatly between different hydroponic systems and different crops grown hydroponically, it is always important to maintain the quality of the nutrient solution. This publication outlines important considerations for understanding, formulating, and managing hydroponic nutrient solutions. This publication is divided into two parts. The first part describes how water quality parameters affect plant nutrient uptake. The second part outlines the management practices you need to follow to prepare nutrient solutions and promote nutrient availability.
The purpose of the nutrition program in controlled environment agriculture is to maintain the plant’s “comfort zone” around the roots. These are the main aspects of maintaining a plant’s comfort zone: • Provide all essential elements • Provide elements in optimum quantities for plant growth • Promote availability and absorption of nutrients
These three aspects often overlap. For example, you may have provided the optimum quantity of an essential element for plant growth. However, a poorly mixed fertilizer or a nutrient solution with pH outside the required range may keep the plant from using the nutrients. Other factors, such as lighting, air flow, dissolved oxygen, air relative humidity and temperature, can also keep plants outside their comfort zones.
Water quality impacts plant nutrition
A nutrient solution is water plus fertilizers. Maintaining good water quality in the nutrient solution is essential to a successful hydroponics nutrition program. The only way to know if your water quality is suitable for hydroponics is to test your water source (Table 1 shows adequate levels for water used in hydroponic systems). Many laboratories offer irrigation suitability testing packages; make sure they include pH, electrical conductivity (EC), alkalinity, and individual elements (nitrogen, phosphorus, potassium, calcium, magnesium, iron, manganese, and sodium). The test report will be helpful for calculating nutrient solution recipes, identifying water treatment needs, and establishing nutrient solution management practices that fit your farm.
To keep crops in their “comfort zone”, you will need to monitor and manage pH, EC, dissolved oxygen, temperature, and water alkalinity. In the following sections we will explain how these water quality parameters impact nutrient uptake and how to manage them to keep your plants healthy.
Download the PDF for the full publication.