Thank you all for responding to my concern.
Bill, since we are practically geographic neighbors, it was good to hear about your experince with this non-native invasive. I think I do recall this dying back in July last year and thought I just did a good job with the Reward. Perhaps, it was going to happen anyway. The reason I now recall some of this is after the curly-leaf pondweed went away (dormant), then the coontail took over. That required a Reward treatment in August.
Please let me know how your Sonar treatment worked out. It's expebnsive, so I hope you don't have to use a lot.
Meadowlark, I hope I didn't lose any carp. I have a screened catch basin at the end of my pond, but if there is a flooding rain, it can overload the pipe and back up the basin. This causes the water to overflow into a field. I do check my field afterwords to see if there are any stranded fish, especially the grass carp, but have never found a carcass. Still, anything could happen.
