I had a pretty significant problem with muskgrass in my 20 acre lake. The chara would grow in water up to about 8 feet deep. It was pretty thick in water 4 ft and shallower. A real pain when fishing.
My water is clear and needs to be fertilized. The concern was that with the substantial weed growth, any fertilization would be sucked up by the chara and be a waste of money. On the advice of Southeastern Pond Management, I stocked grass carp last spring to bring the chara under control, with the plan to fertilize this spring and also stock threadfin shad. I need the shad to boost my forage base as I have a typical bass-crowded situation.
I must say that I am amazed at the progress that the carp have made on the chara. The weed problem this year was nowhere close to what it was last year.
Hope this helps.
Bill