Hanna Alkalinity!!

[Delphinus]

That is AWESOME. I remember reading about how an alkalinity probe (like that used for controllers etc.) would likely never happen on account that the physics just isn't there (or maybe practical) to convert an alkalinity value into a 4-20mA signal but when you stop to think of it, all hobbyist alkalinity test kits are colour based anyhow so why not a colorimeter based tester instead?

The real question I have is how easy is it to use. Of all the testing available, alkalinity has to be one of the easiest tests one can do so to compete with that it has to offer something more. If ppm of 0 to 250 translates to dKH 0 to 14 and a resolution of 0.1 on the unit means a resolution of about 0.2 dKH, with an accuracy of 5% in the 4.2 to 14 range, that means you can tell if your tank fluctuates from 8.0 to 8.1. Which might be useful, I suppose (to be honest though I am happy to the nearest whole dKh point). But if it's super easy to use .... sure sign me up!