The grass carp of about 2/ac was a good number to start with for reducing but not eliminating some of the weed community. You can always add a 1 grass carp per acre when the weeds become more than 40%-45% coverage. Ideally fishery research indicates that around 30% weed coverage is best. IMO the more weeds that are present the less filamentous algae that will be present. Rooted vegetation keeps string algae reduced as it uses nutrients and competes for space.


aka Pond Doctor & Dr. Perca Read Pond Boss Magazine -
America's Journal of Pond Management