Grass carp are a viable and economical means of controlling the growth and spread of certain aquatic weeds. It is critical that problem weeds be properly identified as a preferred food for grass carp, or they may not provide acceptable control. When stocked at low to moderate rates, grass carp will not muddy a pond as do their cousins, the common carp. They typically will not disturb the nests of other fish (bass and bream), and they are not predatory, so there is no concern about their eating desirable sport fish.

Once carp reach 20 to 30 pounds, their effectiveness as a weed control agent is diminished, since their food consumption is reduced and they are not growing as rapidly as do the smaller fish. Thus, periodic restocking (5- to 7-year rotation) may be required for permanent weed control. This, however, still represents a substantial cost savings over the use of chemicals, in many situations.

Large grass carp are powerful fish and can be dangerous if you try to catch them with a seine or a net. They are strong jumpers and will jump over a seine if cornered. In these situations, they can become "flying torpedoes" and can cause injury to humans. For this reason, remove grass carp by hook and line, or by shooting with arrows, spears, etc. In general, once grass carp have reached large sizes, remove them if and when they are caught (by fishermen).

Although grass carp sometimes take on off-flavors from their diets of aquatic plants, their flesh is firm and they do not have excessive intramuscular bones. Many consider them to be excellent table fare!