So what did we all learn tonight/today?
Test your test kits.
Are they "good enough"?
No, they are not always, sometimes, but you cannot rely heavily on them without first running at least 3 points of calibration.
I hear so called folks "in the know", actually folks that really should know better, as they give advice, often are trusted etc, tell folks that the test kits are "good enough".
Unless you have run calibrations on many of these various brands(I know of very few that have and when pressed, it's pretty obvious most do not even know the fundamentals of calibrations and think they know enough about plants not to have to do the basic work involved), you will not know.
There's a huge difference between trying things out, testing them yourself etc versus assuming they are correct.
It's not so much that folks are lazy or do not want to be bothered, it's when they insist and get their pride and egos involved and like to argue/insist that the cheapo test kit is good enough and likely right for "our purposes".
Just admit they are not right unless you run a calibration.
That is a reasonable logically method, just like when you calibration a pH meter with 2-3 point references solution.
Why the heck is okay for the pH meter but not for all the cheesy test kits?
Good grief Charlie Brown.
Put the ego aside and do the right thing for the hobby.
You get far less chasing after meaningless data/incorrect data, wasting time etc. You get much more reliable data, that is useful to the hobby etc.
Folks that do not like to test or bother, use a method like EI.
It can be modified and used in any situation that can implement large water changes.
Which approach/suggestion for test is better for the hobby?
Even a calibrated pH meter is re measured monthly.