Grand Lake's water appears mottled after liquid alum was applied at Harmon's Landing this morning. Alum is expected to cause phosphorous in the water to bind together and sink to the bottom, taking away the main food source for the lake's toxic blue-green algae. Two more sites at Otterbein Retirement Community were also treated today and sites at the Mercer County 4-H camp and the West Bank boat ramp will be treated Friday.