Pond Boss Forums MANAGING AN EXISTING POND Evaluating and adjusting fish populations Grass Carp, Does this make any sense ?

One more slight issue. I don't know what type of algae you have, but grass carp are rated low as far as effective control on most surface stuff, even if they eat it. DW fits that bill. And they really have a low preference and are rated low on primrose. So even if they are eating the dw, they don't control it well. I think what you have is an experimental result of what grass carp control well, and what they don't.