I bought a 50lb bag of Copper Sulfate crystals/powder and would like to begin treating a 4 acre lake that was freshly dug last summer. I'm starting to see some green stuff around the perimeter and wanted to get ahead of it. The landscaper that I purchased it from suggested that I pour about 10lbs inside of a pillow case and then tie it off with a rope and drag it around the perimeter of the lake which would allow it to diffuse into the water. Alternatively, I've read that it should be mixed into a tank sprayer with hot water and sprayed around the lake. Some say they sprinkle the crystals or powder with a broadcast spreader or by hand sprinkling. Just wondering if there is a "best" method to this before I give it a go this weekend.