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"Poisonous" does not mean deadly. Some manifestations of toxicity are subtle. The dose, as always, determines if a plant is safe source of nutrients or a toxic hazard.

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BRIEF: Are the tannins in my well water dangerous?

I have been told that my well water supply has tannins. Is this harmful for humans, horses, or dogs to drink? It has been suggested that we install a charcoal water filter in front of a water conditioner. Will this really remove the tannins from the water supply?


If I had tannins in my well water, I would wonder if it was so shallow under fractured rock that wood leachate and other surface contaminates weren't running into it. Or is it drilled into a peat bog or what? The charcoal would probably take out a lot of the tannins.