"Pi water" is not a recognized term in the scientific or water treatment community. There is no evidence to support the existence of a type of water called "pi water" or that it has any special properties.

It's possible you may have encountered this term in a pseudoscientific or marketing context. Some companies may use misleading terminology to promote their products, and "pi water" could be a made-up term used to create an air of mystery or scientific validity.

If you're looking for information on water purification or treatment methods, it's best to consult reputable sources like scientific journals, government agencies, or established water treatment companies.