Are nutrients required for ideal microbial growth?

The ideal condition requires the presence of specific concentrations of Nitrogen, Phosphorus and micronutrients in the wastewater. Prior to an application laboratory tests are suggested in order to determine a possible nutrient deficiency. Urea and Triple-super Phosphate are used to create the ideal ratio of COD:N:P which is 100:5:1 or even 200:5:1.