Dissolved oxygen concentration is perhaps the most important variable influencing the well-being of fish, shrimp and other aquatic life.
water quality standards
Biochemical oxygen demand is an index of the oxygen demand in wastewater, an important water quality variable used in effluent management.
For seawater or brackish water aquaculture management, the salicylate method is best for total ammonia nitrogen analysis.
Two nutrient elements, nitrogen and phosphorus, are responsible for eutrophication in most instances. Phosphorus is usually the key factor.
Solids in water are either in true solution or suspended. Suspended solids remain in suspension because they are so small and light.