The dataset contains spectrophotometrically measured chlorophyll absorbance data from lake and river samples incubated with different nitrogen, phosphorus, silica or combined nutrients, as bioassays, either ex situ for phytoplankton or in situ for periphyton. These data were collected from sites in the English Lake District, Norfolk Broads and Greater Glasgow area in 2017 and 2018 as part of the NERC funded Freshwater Highlight Topic 'Hydroscape'. The work was supported by the Natural Environment Research Council (Grant NE/N00597X/1). Full details about this dataset can be found at https://doi.org/10.5285/2ea22f99-242c-4524-a5dc-3067a5f97a72
