Selecting hydroponic nutrients for the garden can be a confusing prospect. There are many hydroponic solutions on the market, so it can be difficult to determine which solution is best for your fruits and vegetables. There are 16 elements that must be supplied for plants that are grown hydroponically. And while carbon, oxygen and hydrogen can be pulled from the air and aerated in to the nutrient solution, the rest of the nutrients must be provided in the nutrient solution.
The remaining 13 elements that growing plants need can be broken into high-concentration macronutrients and low-concentration micronutrients. Plants need nitrogen, phosphorus, potassium, sulfur, calcium and magnesium in high concentrations, and chlorine, iron, manganese, zinc, boron, copper and molybdenum. Some plants may also need aluminum, silica, selenium, cobalt and vanadium to thrive. Fruit and vegetable crops need lower levels of nitrogen than leafing crops, such as lettuce.
Pre-Mixed Nutrient Solutions
Beginning gardeners may select a pre-mixed nutrient solution that has been formulated for hydroponic systems. Some pre-mixed nutrient solutions are created specifically with the right blend of elements for fruits and vegetables. These solutions are typically mixed with water and then added to the root chamber of a hydroponic system. Because plants need different amounts of macronutrients at different points in their growth, specific concentrations of nutrient solutions should be purchased and added to plants during different periods of the plant's life cycles.
For more control over the quality and quantity of nutrients that plants receive, some hydroponic gardeners chose to mix their own nutrients. Many of the elements used in home mixed nutrients can be found in unlikely places. For example, saltpeter used in gunpowder is one source of potassium nitrate. Calcium sulphate is scientific name for plaster of Paris, and magnesium sulphate is commercially known as Epsom salts. The nutrients should be mixed carefully and then diluted with the proper amount of water. Too little water can create a solution that is toxic to plants. You should also check the pH of your nutrient solution before adding it to the rooting chamber. Most nutrient solutions lower the pH of water. The liquid should be pH neutral to help the plants thrive.