The "stringy" stuff you describe sounds like filamentous algae. Don't expect to have much luck removing it by hand. Try applying one of the chelated copper products, readily available through one of our advertisers.

Neither should you expect grass carp to eat every green stem in your pond. That seldom happens. It COULD, of course, but only if the fish are introduced in extraordinarily high density, in violation of state regs limiting grass carp to the max stocking rate of 7/acre.

Better, analyze your pond. You sound as though your pond is ultra-high in nutrients. Find out why.

Do you have lots of livestock? If so, in the interest of a fishery, fence them out of all but a small area at the upper end where they can come to water.

Mark McDonald
Editor, Pond Boss