Yes. In hydroponics, plain water is not a complete growing solution for most crops. You normally add a complete hydroponic nutrient formulation that supplies the essential mineral nutrients plants would otherwise obtain from soil.
What Do You Add to Hydroponic Water?
Use a hydroponic fertilizer or nutrient system designed to provide the required macronutrients and micronutrients. These typically include nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, manganese, boron, zinc, copper, molybdenum, and other essential elements in appropriate proportions.
Do You Need Extra Additives?
Not necessarily. Start with a complete nutrient formulation and suitable source water. Products marketed as boosters, supplements, enzymes, sweeteners, or root enhancers should not be treated as mandatory. Add something only when you understand why it is needed and how it affects the full nutrient solution.
Mix Nutrients According to the Product Directions
Do not guess nutrient concentration. Follow the manufacturer’s mixing instructions, then monitor pH and electrical conductivity (EC). Crop type, plant age, water quality, temperature, and system design all influence the ideal nutrient strength.
Source Water Matters
Tap or well water may already contain calcium, magnesium, alkalinity, or other dissolved minerals. Very hard, salty, or softened water can complicate nutrient management, so test the starting water when problems occur.
Bottom Line
For most hydroponic crops, add a complete hydroponic nutrient solution to suitable water. Avoid piling on optional additives until the basic nutrient program, pH, EC, light, temperature, and root-zone conditions are working correctly.
Source: Penn State Extension — Hydroponic systems and plant nutrition.
