I usally try to avoid using chemicals if I can help it but the FA is going crazy with the in the upper end of the pond and blowing clumps all over it. So i mixed up about 8 oz in my 3 gallon backpack sprayer and sprayed about 75-100 yards of shoreline where the FA was getting bad at. The pond is 6 acres and I was wondering how dangerous just spot spraying a small section is to the fish. I know copper isnt good for them. Would reward be a safer chemical to use?