There may already be a thread on this subject, if so I appologize. I am needing to kill cattails in a couple ponds that have a good fish population. I know that any Glyphosate product will kill the cattails, but I am worried about it killing the fish as well. I know Rodeo would probably be my best option since it has more surfactants in it and is approved for use around water, but I can not hardly justify the price unless it is my only option. Someone told me that they used a very diluted solution of Roundup and that it didnt harm any fish, but I find that hard to believe. Anyone out there have any suggestions??