Did ancient Persians boil water for safety?

[Alanus]

If the ancient Indus knew about purifying water, there's no reason to assume Cyrus didn't. His tribe was the Medes, although he ended up as the king of Persia; and like the Indus, the Medes came off the steppes where Zarathura was born.

The "fire and water" (in the post above)is interesting but might be overstating a rather simple precautionary measure-- avoiding dysentary.

OR!-- perhaps Cyrus liked the particular taste of water from than river. Kinda like someone today drinking Perrier water in preference to Polad Spring water.