Mini Secchi app and disk


The mini Secchi disk is a small, circular disk that is used to measure the transparency of water. The Secchi disk is named after its inventor, an Italian astronomer named Angelo Secchi, who developed the tool in the 19th century. To use a mini Secchi disk, a person simply lowers the disk into the water until it is no longer visible, and then measures the depth at which the disk disappears. This measurement can be used to estimate the transparency of the water, which can be an indication of its quality.

The mobile App is developed with support of the MONOCLE H2020 project to collect photos and the disk has been expanded with a clip to attach pH paper. 

Data is processed by the Plymouth Marine Laboratory and shown on a map here:



Collect observations of water quality and colour for fresh water ecologists. 

Needed equipment

A (mini) secchi disk

A smartphone (Android/iOS) with the Mini Secchi disk App

About funding

Funding bodies: European Commission

Created Jan. 27, 2023, 2:22 p.m.

Updated Feb. 20, 2023, 7:30 p.m.

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