It depends on the quality of water going in. Tap water is typically better the further north you go IMO. Here in Florida, my zero water pitcher will only be good for a few gallons, but it could last longer for others. Distilled water is only $0.80/gallon at Walmart.
The exception is North Dakota. I've gotten 30 gallons out of 1 filter here in Colorado with 200ppm TDS reading. 30 gallons of distilled here is 98¢ a gallon. I buy filters on ebay on average of $11 a filter. The more you filters you buy the better the deal. Better yet think of all the plastic you're saving on the environment.
Also true. I think my water is 400-500 ppm out of the tap. I’m starting to look into those refill stations in grocery stores where you can refill your jugs.
