Make it easy on yourself right now before it gets out of control....it will give you time to decide if you can do something more permanent.
go to coppersulfatecrystals.com (they also sell on Amazon now) and get the "small" crystals, 50 lb. bag, delivered to your door for about $130. You need to use 15 lbs. per surface acre for initial spring treatment>
Put crystals in doubled burlap bag, tie a rope onto the bag and use your jon boat to drive around the edges of the pond as the copper sulfate dissolves in the burlap sack. 10 days later it will be clean as a whistle. You can follow up every 3-4 weeks with 7 lbs. per acre. BM61.
BM61 have you ever tried broadcasting the copper sulfate crystals as is done with Cutrine Plus granular? I just bought 20 pounds of the copper sulfate crystals and want to know what my treatment application options are.