This dataset comprises silica concentrations in water from Loch Leven, Scotland, between years 2007 and 2023. Loch Leven is a lowland lake in Scotland, United Kingdom. The data were collected as part of the long-term monitoring programme, which began in 1968 and is still underway. Sampling and analyses were conducted by UK Centre for Ecology & Hydrology (UKCEH). The data collection and processing were supported by the Natural Environment Research Council (NERC) award number NE/R016429/1 as part of the UK-SCAPE programme delivering National Capability. Full details about this dataset can be found at https://doi.org/10.5285/38e5d47b-9efb-44fb-8860-7fc4d885ab02