Shields08, 50# of alum per acre foot of water volume will reduce the P in the water and take some of the algae to the bottom to die. Fertilizer, as you now know, is tricky...low doses are always best till you get the bloom wanted. Adding 50% hydrated lime, sprayed in "strips" about 5' apart will shock and kill algae also, often creating a thick froth on the surface from carbon dioxide expulsion. The first rain cleans it up.
Last edited by Rainman; 04/17/17 01:50 PM.
