The proper nutrient solution is critical to the success of a hydroponic garden. Common garden fertilizers are not suitable for use in a hydroponic system because they are formulated with the assumption that your plants will be getting some nutrients from the soil. Because there is no soil to provide even trace minerals, a hydroponic solution must provide all the elements that a plant needs for proper growth. You can purchase ready-made hydroponics fertilizer or you can mix up your own with ingredients from a fertilizer company or a hydroponic supply store. This solution is specifically for vegetables and other rapidly growing plants.
Put 10 gallons of water into a mixing barrel. Make a macronurient solution by adding 2 level tsp. of ammonium phosphate, 4½ tsp. of calcium nitrate, and 4 level tsp. each of potassium nitrate and magnesium sulfate. Stir until all the compounds are completely dissolved.
Measure 1 quart of water into a 1½-quart container. Mix 1¼ teaspoons of boric acid and 1/10 teaspoon of manganese chloride into the quart of water. Stir well and then take ½ cup of this and pour it into your macronutrient solution from Step 1.
Add 1 quart of water to a separate 1½-quart container and stir in ½ teaspoon chelated iron. Put 3/5 cup of this iron solution into your macronutrient solution from Step 1.
Stir the macronutrient solution well and place the pH meter into the solution. Read the meter. If the solution has a pH greater than 7, it is too alkaline. Add a few drops of white vinegar to the solution, stir and check the pH again. Conversely, if the solution has a pH below 5, add a scant teaspoon of baking soda to the solution, mix well and check the pH again. If needed, continue adding vinegar or baking soda in small amounts, mixing and rechecking the solution until the pH is between 5.5 and 6.5.