Spraying is like a double-edge sword. Some of the places one catches fish for years gets over-taken by the weeds/grass and U just can't get to the fish. As it spreads, one knows action must be taken before other places get covered and effects the fishing. Years ago one of my favorite creeks in Talquin they sprayed to knocked-back the lillys and other weeds. It big-time altered the fishing in the upper end of this creek. It's just recently came-back to catching good fish again.