Humate Supreme™ 3-2-1 is basically the Humate Supreme™ Humic Acid Plus with a minimal amount of NPK added, boosting the tablet to a complete stand-alone nutrient rich plant food product. Humate Supreme™ 3-2-1 is a "fertilizer" by definition, complete with all the NPK and trace nutrients needed to grow the plant to maturity. With Humate Supreme™ 3-2-1 we highly recommend against adding any additional nutrients, especially NPK. If visual examination, or petiole analysis, indicates additional feeding is required, just add another tablet. When using this product in a hydroponic system, use the hydroponics for watering only.