Many hydroponic formulas have been developed over the past 40 years with some designed for specific plants while others are designed for general hydroponic gardening. For plant growth, the concentration of individual elements must stay within certain ranges that have been determined through scientific experimentation.
The average concentration of these elements should fall within these parameters:
- Nitrogen (nitrate form) 70 -300 PPM
- Nitrogen (ammonium form) 0 -31 PPM
- Potassium 200 -400 PPM
- Phosphorous 30 -90 PPM
- Calcium 150 -400 PPM
- Sulfur 60 -330 PPM
- Magnesium 25 -75 PPM
- Iron .5 -5.0 PPM
- Boron .1 -1.0 PPM
- Manganese .1 -1.0 PPM
- Zinc .02 -.2 PPM
- Molybdenum .01 -.1 PPM
- Copper .02 -.2 PPM
*PPM = parts per million
Hydroponic Nutrient Mixes
A gardener can purchase all of these minerals separately and mix their own hydroponic fertilizer. Unfortunately, the fertilizers that make up a hydroponic formula aren't sold as pure nitrogen or pure potassium, so it gets more complex. They are sold as chemical compounds, such as calcium nitrate, potassium nitrate, magnesium sulfate, potassium sulfate and mono potassium phosphate.
Since there are many dependable pre-mix hydroponic formulas available, it is generally more efficient and more economical to use a proven formula that contains all of the above mentioned nutrients in the correct quantities for plant growth. one that you simply add to water.
Whether you are using a pre-mixed formula or creating your own" it is important to follow these guidelines:
- Weigh or measure the nutrients carefully.
- Place the nutrients in separate piles or containers to be sure the proportions make sense.
- Be sure no components are left out or measured twice.
- Accuracy should be within 5 %.
- When you are sure the proportions are correct, pour your nutrients into the water in the mixing containers and stir vigorously. Nutrients will dissolve best in warm water.
- Measure the nutrient concentration level and record it.
Listed below are a variety of nutrient mixes to get you started, you can also read through our Getting the Best out of your Nutirents article for some great tips on where to start and how much to spend.