The Secchi Disk


What is a Secchi Disk?

What (or who) is a "Secchi"?

Why are many disks black and white?

Considerations in Secchi Disk Design

Considerations in Secchi Disk Procedure

Methods Used in Monitoring Programs

Evaluating Eutrophication by Secchi Depth

Purchasing a Secchi disk

Making your own disk

Secchi Records


Other Secchi Disk Resources


If you would like more information on using the Secchi Disk or on volunteer monitoring, the EPA maintains an on-line Volunteer Monitoring Manual. Be sure to check out this site if you are considering monitoring your lake. 


For more information on the Great American Secchi Dip-In, contact us at: or write

Great North American Secchi Dip-In
Department of Biological Sciences
Kent State University
Kent OH 44242