Grass Carp are hard to keep in the net. Pond crews need to be careful not to get hit by airborne Grass carp trying to escape the net. We use Grass Carp as a low cost alternative to herbicides. These fish are susceptible to predation both from larger fish and birds. Grass Carp are a fast growing fish that can 20 plus pounds in a few years. Tripliod Grass carp spend their time on the bottom eating.