So when I do the API liquid pH test I get a certain number right away. I assume that to be the correct reading. Now I can violently shake the test into a froth and artificially lower the reading. That makes sense, too. But why does it drop just as far with water I've buffered as it does with the 0 hardness water from my tap? Shouldn't the buffered sample be unable to drop as far? Oh, and breathing into the tube's remaining airspace while capping it does cause the test to bottom out as the CO2 gets mixed in. But, again, I thought that hardness would battle that effect. So why doesn't it?
