LaMotte Secchi Turbidity Disk, 20 m cable

Simple-to-use secchi disk is a weighted, 20-cm dia black and white plate that sinks parallel to the water's surface. For best results use, from the leeward side of a boat or dock between mid-morning and mid-afternoon. Use to determine turbidity or degree of visibility in natural water supplies Braided, stretch resistant line marked at half and full meter intervals up to 20 meters