The tests are not electronic. these are small portable colorimeters probably each tuned to the narrow wavelengths of the particular test they do. So it is just a replacement for our test tube tests. but in the case of things like phosphate, nitrates etc. wher you are trying to match a colour these are most likely more accurate as they don't depend on the colour temperature of the lighting you are doing the test under and a judgement call of what you think the colour is etc.

For stuff like Alk and Ca and Mg that are titration tests with a distinct colour change the advantage might lie in greater precision (which we'll know once they release more information about the checkers) and convenience.

The ease for these tests isn't necessairly in preparing the tests. In fact, they're probably largely the same. But ease lies in the reading - most likely more accurate than judging colour by eye, and because they are most likely not titration-based, will allow for more precise readings. As well, it's repeatability - for the colorimiter, it's going to be fairly consistent day to day. For test kits, the result is only as consistent as your interpretation of the resultant colour.

Yeah to have probes to monitor it real tim would be great. Tied to my dosers, parameters would always be rock solid in a very small range, and you'd just have to recalibrate once in a while as opposed to testing a here and there.

Elos had a colorimeter planned but they canceled it because it would have cost more then consumers would pay for them.

Cheers,
Vic