I did not buy any yet. Just read the label at the store. Nobody there has an idea, just said to follow label directions. I thought someone here could answer pretty quick about how much should be mixed into a gallon because that is probably all I need. No tilapa in the US that Im aware of except on your dinner plate. Grass carp are common around here but I don't like the idea of carp in my pond. Would rather just spray it. Thanks for you responses though.