That was an interesting video, I'm sure useful for saltwater people. He wasn't rinsing the meter in between glasses, so that's why he got a reading of 1 on the RO
And about Prime being so great, I see it as a highly concentrated product that is backed by a company that is throwing out other great products. The Clarity product worked lovely for me, amoung other things. I feel more comfortable spending my money on brands that actually work than buying a lower-grade dechlorinator that comes from a brand that has caused me to almost throw stuff out of the window (I.E. filters).