Grass carp don't particularly like filamentaeous algae but will eat it if they have not much else to eat. Tilapia on the other hand will clean it up. Last year when I had Tilapia I had no FA, this year I couldn't get any and my pond is loaded with it. I know people argue about stocking rates, but 8 doesn't seem like enough for 3 acres if you have much vegetation. Dave is right the bigger they get the less effective they are.

In Dog Beers, I've had one.