Can anybody tell me if they think pond dye will kill off the Chara? I have used 25 pounds copper sulfate on the 2 1/2 acre pond, but it hasn't killed it off. 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. I have Koi & Talapia but they haven't put a dent in it.