I've never heard of anyone buying one. They're too easy to make. Get a white disc like the top of a 5 gallon plastic bucket. Almost anything will do. Bore or poke a hole through the middle and run a piece of cord through the hole. Tie a weight of some kind to which ever side will be the underside. You have a sechi disk. Lower it into the water until it disappears and measure the amount of wet string.

It's not about the fish. It's about the pond. Take care of the pond and the fish will be fine. PB subscriber since before it was in color.

Without a sense of urgency, Nothing ever gets done.

Boy, if I say "sic em", you'd better look for something to bite. Sam Shelley Rancher and Farmer Muleshoe Texas 1892-1985 RIP Grandpa