Grass Carp are usually an all or none proposition when it comes to weed control, either you have too many or not enough, happy mediums are hard to find. In our case the GC seems to have had very little effect on the pond weeds. We have milfoil, sago, coontail, stonewart, and what I think is crowsfeet in our pond (not to mention the duck weed, filmetous algea, and catails). We have around 60-75 GC in the pond. Right now we have scattered coontail growing off the bottom of the in 11 feet of water, we frequently have weeds growing all the way to the surface in 6-8 ft of water. Grass carp do have a preference for certain typs of weeds, coontail and milfoil just happen to be at the bottom of their preference list for edible plants.
