I put in 10 GC in my 3 acre pond about 3 months ago. My pond was completely overgrown with coontail. Now it's completely clear. I was worried that I overstocked GC but when I cast out my lines I still get coontail caught in it so I guess that means there's still some good stuff for them to eat and they haven't devoured all of it yet. Also the water is very clear so I havent noticed any turbidity caused by the GC