All,

I currently have a 1 acre pond that I use for drinking water. It's about 10 years old.
I aerate it and add microbes on a regular basis.
Water is crystal clear but over the years the Chara is getting worse.
I generally rake it out, but it's starting to become a chore.
Is there any herbicide that can be used in drinking water that will control this issue?

Thanks in advance.