Determine how clear the water is. Real equipment as used by the professionals. 200mm Disc four quadrants 2 black, 2 white with plenty of line lower into water. Our sturdy plastic Secchi disk handily meets industry standards.
It is 200 mm in diameter (7-7/8) and has four quadrants, two white and two black. We include 20 meters of 1/8″ diameter line on an orange styrofoam form that will float if dropped in the water. Plus instructions that are written at a basic level.
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