Basics of Nutrient Management for Hydroponic Growers

Hydroponic nutrients are at the core of good crop management

Hydroponic systems are designed to conserve more water and in return provide huge efficiencies because it uses water as the main delivery method of plant nutrients. As nutrients are more directly available to plants, hydroponic systems can eliminate nutrition-based bottlenecks to production. This increases the growing potential of the crop in the systems, making Nutrient Management the cornerstone of a well-run Hydroponic Farm

So what exactly are these plant nutrients?
Plant growth, function and reproduction relies on 16 essential nutrients.

of these 16 nutrients are available through air (CO2) and water (H2O), I.e., Carbon, hydrogen, and oxygen. 

The remaining 13 nutrients are the mineral salts delivered to plants dissolved in a solution. These essential nutrients can be broadly categorized as:

- Primary macronutrients, the most abundant building blocks in plant
growth and reproduction. The primary macronutrients are nitrogen, phosphorus, and potassium, or NPK.

- Secondary macronutrients, which are also necessary, but in smaller amounts. The secondary plant nutrients are Calcium, Magnesium, and Sulfur.

- Micronutrients, which are required in very small quantities for growth and reproduction. The micronutrients are: Boron (B), Chlorine (CI), Copper (Cu), Iron (Fe), Manganese (Mn), Zinc (Zn), Molybdenum (Mo)

There are important parameters involved in Nutrient Management:

The very first step for hydroponics is to have the water analyzed by a lab or on-site using a reliable pH and/or ppm pen. Poor-quality water can cause nutrient toxicity or deficiency problems initially or later in production. Water naturally consists of salts like sodium, calcium, magnesium bicarbonates, chlorides and sulfates. These salts can affect EC and pH of the nutrient solution and should not be above the acceptable level for the appropriate crops.

  • pH of Water and Root Zone

pH is a measure of how acidic or basic the solution is at the time of reading. The range goes from 0 to 14, with 7 being neutral. The pH of a nutrient solution influences the availability of nutrients, so it should be maintained in the optimum range.

Ideal pH for Soilless growing is 5 to 6 (usually 5.5)
Ideal pH in the root zone is between 6 to 6.5. This is the pH range at which nutrients are most readily available to plants.

  • EC of Media

EC or Electrical Conductivity is how well a solution transmits electricity. The overall nutrient level in a solution is measured in EC. First, let’s look at what electrical conductivity (EC) actually is. Now, you probably already know that water conducts electricity, but the REASON it does so is pretty interesting. In your water, there are usually traces of all kinds of minerals: calcium, iron, potassium, magnesium – your water contains much more than just “H2O”, and those extra particles are actually what conducts electricity. In fact, pure water is a terrible conductor! Distilled water, de-mineralized water, and usually even rainwater will give your EC meter a reading of 0.0, indicating that they contain no trace elements.

The necessary water quality depends on the crop grown, how closely the fertilizer used matches crop needs. And if it does not match closely nutrient imbalances can occur, building up to toxic levels.

Hydroponic nutrient tools

There are a multitude of handheld measuring devices and testers. Our favourite and voted as the most preferred brand by growers is Bluelab. Measuring these parameters is essential and the basis to manage Nutrients in your hydroponics operation. Tools are available to measure these parameters (EC pen, Conductivity Pen) easily and accurately. 

You’ve learned about the 13 mineral nutrients, EC and pH, and tools to manage nutrients. Get an edge on hydroponic management by learning and testing these basic lessons in your hydroponic growing operation. 

This should put you on the right road to being a great hydroponic manager. 


Back to blog

Leave a comment

Please note, comments need to be approved before they are published.