*3.7.1.7 Quality control*

Proper sample handling, preservation, and storage are essential to maintain the integrity of collected samples. Quality control measures ensure that results are reliable.

### *3.7.1.8 Nutrient ratios*

Besides phosphorus concentrations, nutrient ratios such as the nitrogen-to-phosphorus ratio (N:P ratio) are often assessed to understand nutrient limitations and potential impacts on ecosystem dynamics.
