Can anybody tell me if they think pond dye will kill off the Chara?
Probably not once it's established for the year. You need to use the dye early in the year before it gets started.
I have used 25 pounds copper sulfate on the 2 1/2 acre pond, but it hasn't killed it off.
Do you have hard water? If your water is hard you should be using a chelated vareity of copper as the regular copper sulfate is less effective in hard water. Cutrine Plus is one example. That said, I have really hard water and even the chelated variety doesn't work that well for me.
The Chara is floating in mats covering about 2/3 pond. I also used a Roundup for ponds but it only killed the pond weed & cattails.
Floating? Are you sure it's Chara? I've never known Chara to float and I have lots of it. And Roundup and other glyposates are not effective on submersed aquatic vegetation.
I have Koi & Talapia but they haven't put a dent in it.
How long have you had them?
