I am mowing an industrial site with a drainage pond in the front. The pond is about half the size of a football field, and is surrounded by aprox. 3 acres of lawn that is sloped toward the pond. This is my first year fertilizing, and I have never had experience with a drainage pond......and, yes, there are fish in it.( Fertilizing previously done by liqui-green). All of the pre-emergents and weed and feed have warnings about being harmful to aquatic life. Don't see any of these warnings on the regular stuff. I must use granular because I have an electric broadcast spreader that fits on the front of my ztr.........I will probably talk to my local Illinois dept of ag extension office, but was wondering if anyone has any suggestions?