Zinc isn't toxic except in massive quantities. There is a very educated lady on this forum that is an expert in parrots and she had some info that suggested zinc toxicity might exist in parrots, but the studies if I recall correctly covered chickens and showed very elevated levels of zinc. Far more than normal which scientists tend to do because the effects are magnified making it easier to get results.
Water with elevated levels of iron or zinc aren't likely to be palatable for chickens.
Still, best practice would be to control what you can and throw the darned thing away instead of worrying about it.
Water with elevated levels of iron or zinc aren't likely to be palatable for chickens.
Still, best practice would be to control what you can and throw the darned thing away instead of worrying about it.