JBL ProScape NPK Macroelements contains nitrogen as nitrate, phosphorus as phosphate, potassium and magnesium for a controlled and precise increase of the values, thriving plant growth and prevents deficiency symptoms. Dosing is dependent on intensity of illumination, CO2 supply and consumption. How to use: Use daily: 6 ml/100 l in high power light + CO2; 3x weekly: 2 ml/100 l high power light/no CO2; daily: 2 ml/100 l in weak light conditions + CO2; weekly: 2 ml/100 l in weak light conditions/no CO2