A daily cycle of tests was conducted to specify the concentration variation of phosphorous compounds and other chemical parameters at surface microlayers of a shallow lagoon lake located on the Baltic Coast. The water for analyses was collected from Lake Dołgie Wielkie in one hour cycles for the period of 24 hours. Samples were collected from the surface microlayers that had a thickness of 80–115 µm and 250–300 µm as well as from the subsurface water at the depth of 15 cm. Data analysis shows information concerning the migration of phosphorous compounds between the analyzed layers. Correlations were estimated for the obtained concentrations of phosphorous compounds and the nitrogen compounds and other physico-chemical values which were described in the first part of the cycle. The content of nutrients in the examined surface water layers correlated with the oxygen consumption due to the value of the oxygen consumption mostly depending on the concentration of organic matter.