Keywords: monitoring Substances: 4-5-Dichloro-2-n-octyl-isothiazol-3(2H)-on (DCOIT) (PORQOHRXAJJKGK-UHFFFAOYSA-N) 5-Fluoro Cytosine (XRECTZIEBJDKEO-UHFFFAOYSA-N) 2-4-dimethylphenylformamide (JOFDPSBOUCXJCC-UHFFFAOYSA-N) 4-Methyl-Benzotriazole (CMGDVUCDZOBDNL-UHFFFAOYSA-N)