Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants Grass Carp - 1/4 Acre Pond

Mrhello, I understand that the 8 - 12 inch range is when they finally start becoming interested eaters that can actually begin to have a positive impact (however you choose to define that) in your pond. They stay effective for a number of years, but it appears that conventional wisdom says that by the time they've reached torpedo size, they've begun to lose a bit of their effectiveness and prefer to float near the surface a lot of the time just sunning themselves. So, I guess my point is that you should have at least a few years of good weed control expectation out of them, if not longer.