I think your only choices are products like Cutrine Plus and manual removal. Mine has been worse than ever this year too. Pond dye seems to help by cutting down sunlight reaching the bottom where it grows. I used the Cutrine Plus granules spread over all water over a couple feet deep and Cutrine liquid around the edges. Just treat 1/3 to 1/2 of the pond at a time to prevent a fish kill from the decomposing FA. It does a great job and I hope it keeps it under control all summer.