All hydroponic gardening systems require a nutrient liquid to provide the necessary nutrition to the plants. All nutrient manufacturers have a proprietary blend, but they all contain everything plants need to grow. Each commercial liquid will contain 15 of the 16 nutrients identified as essential to plant life, though the sources of those nutrients will vary depending on the manufacturer. Some nutrient solutions will be natural and organic solutions, while others will be a chemically based formula. Carbon is the only element you will not find in the nutrient solutions, as the plants will obtain that from taking carbon dioxide out of the air.
Most of what you will find in hydroponic liquid is water – because the plants absorb the water from the solution to get the hydrogen and oxygen the plant needs to grow. The water should be clean and free of any dissolved solids. Ideally, the water’s pH needs to be somewhere between 5.5 and 7.0 pH.
Primary Nutrients in Hydroponic Liquid
Most fertilizers use nitrogen, potassium, and phosphorous as the primary nutrition, because these are what plants need the most of. The ratio of nutrients will vary from plant to plant, and will also vary from growth stage to growth stage. Plants will require more phosphorus during germination. Potassium is required for photosynthesis. Nitrogen is required during the heavy vegetative stage.
Secondary Nutrients in Hydroponic Liquid
Plants require other nutrients in smaller amounts – including calcium, sulphur, and magnesium. Calcium is a part of the plant’s cell wall. Sulphur is a critical part of the plant’s proteins and vitamins. Magnesium is required for photosynthesis to take place.
What About Micro-nutrients?
These are nutrients the plant needs, but in much smaller amounts. Micro-nutrients include: iron, copper, chlorine, manganese, zinc, boron, and molybdenum. In small amounts, plants thrive. In large amounts, however, these nutrients can kill plants.
There are many other nutrients that though are not considered essential to plant life, are beneficial for keeping plants healthy and growing to their potential. These nutrients are sometimes, but not always, found in nutrient solutions to provide an extra “boost” to the plants. Other nutrients include: Cobalt, sodium, vanadium, and silicon. The additional nutrients may not be beneficial, depending on the plant(s) you grow – so check the nutrient solution to be sure it is the best option for your intended crop(s).
What Does pH Matter?
The pH of a nutrient solution must be just right for the plant to make the most of it. If the pH is too acidic, or too base, the plant may not get enough of certain nutrients, or may not make use of all the nutrients it has. To balance the pH for optimal plant growth, additional chemicals can be added to the solution. The pH balance will vary depending on crop, but for the majority of plants, a pH range of 5.5 to 6.5 is ideal. Check the pH and adjust regularly.