Hey, Silverados, I just received the "free" Hanna TDS meter and took free trial on the "Zero Water" filter. I've got some interesting results and I'd appreciate any learned comment.
I'd read on the list that the Hanna meter may not detect dissolved salts below, say, 10 ppm, thus it would have a 10 ppm minimum resolution. To test this, I gather samples of tap water, filtered tap water (through an Equinox unit), commercial distilled water, my last CS batch, and water from the Zero Water filter. The meter readings: Tap - 142 Filtered tap - 136 Distilled - 000 My CS - 002 Zero Water - 000 Then I made a batch of CS using the zero water as medium. The result was clear 003 ppm with excellent Tyndall. 48 hours later it's still clear and looks perfect. The anomaly: I made a second batch of CS using zero water I had stored in the plastic accordion jug (that milky white plastic) that came with the zero filter. The result was almost immediately cloudy and got worse from there. Then I went out to dinner, forgetting about the batch I had running. It brewed for about nine hours unstirred and, of course, turned blackish brown. I filtered it through a paper towel and then metered it at 16 ppm. It'll likely be used for cleaning and external spray applications. I assume the cloudiness of the second batch was caused by whatever outgassed from the plastic and dissolved in the water after the filter did its work. I"m going to make another batch from fresh filter output and I'll let you know the results if there's interest. I'd love to hear opinions, especially regarding the likely minimum resolution of the Hanna meter. I've searched the Hanna site and others and can't find any coherent specifications for it anywhere. How un-scientific. Pooh. Sam
