i recently got a red sea pro reef foundation kit and i love it! its just alk cal and mg...but compared to other kits ive used or have on hand the red sea pro kits are pretty accurate....
I agree that a master test kits is a pipe dream. I agree again API for alk(the titration is so simple many companies have good kits. I just like the one I can get a little cheaper). Cal and mag I like Salifert. Phosphate Hanna checker 713 is good, but can be fustrating. Other element testing goes even deeper. Over all it really is a personal choice. Follow the trend and remember exact numbers are not recommended to chase.
I do the API kit with, preferably a Salifert kit for mag. I have an Elos now because they were out of the Salifert kits when I needed one last time and I wish it was the Salifert kit.
ive used the elos for mg...and the red sea is on point. ive used the salifert for alk and the red sea is on point...for calcium i have used api..salifert...and the redsea...all about the same for calcium