[pandoraou812]

They added it to my water a few years ago. I had a leak in my koi pond & added hose water. Killed 25 of my koi fish. Now I have to use an additive when using my hose water to fill the pond. I was going to get a rain barrel but I am trying to sell & it is winter. I liked my water just fine & liked it even better when I could use my well. However Brick decided to outlaw well water for the house. We can use it for the grass. I always forget as it is just hooked up to my sprinkler system now.

[telebob]

"They added it to my water a few years ago. I had a leak in my koi pond & added hose water. Killed 25 of my koi fish. Now I have to use an additive when using my hose water to fill the pond."

That's an attribute of chloramine, not fluoride. Chloramine is used as a disinfectant. It's a compound comprised of chlorine and ammonia, typically in a 4 to 1 ratio. Very harmful to aquatic life but not harmful to humans or their pets.

You're most likely adding sodium thiosulfate to neutralize it.