I bought some replacement gallon jugs of water from what is here in Southern California as Food4Less but is owned by the Kroger Foods Co and this water tested right out of the store at 0ppm, this is this first water that tested at zero, I have had lows of 6 before but for .50 a gallon you can't beat it for CP's.
I typically just go to the RO vending machines in front of grocery stores. I just refill 6 one gallon jugs and it only costs $0.25 each gallon. My PPM on the water is 0. Saves money, saves plastic, and is always available.