Control of aquatic plant nuisances (especially algae) with some substituted phenylureas

Summary

Higher submerged water plants and filamentous algae can be controlled very well by the application of diuron as early as April in a dose of from 0.2 to 0.4 ppm. In order to control micro-algae in swimming pools and to obtain a transparency of from 100 to 250 cm a higher dose is necessary, the growth of Crustacea, which eat small algae i. a. being desirable at the same time. The addition of diuron should be effected in clear water preferably with an initial dose of 1 ppm. In some of the smaller swimming pools the concentration of diuron had to be kept above 0.6 ppm in order to obtain a transparency of from 120 to 240 cm. In a large swimming-pool (6,000 m³) a transparency of from 170 to 270 cm could be maintained even during the time when the diuron in the water was no longer detectable.