Recommended level: max. 1.0 mg/l in freshwater.  Highly sensitive test for measurements with laboratory accuracy.  Indicates the phosphate content of the water, responsible together with nitrate lebel for the undesirable growth of algae. Measurement range begins as low as 0.05 mg/l.  For approx. 50 measurements.  Includes glass cuvettes, comparator system, syringe and colour chart."