Very interesting, Greg.
While the Seachem Reef Status tests are a production (you should see the magnesium test

), I'm curious as to why you feel the Reef Status calcium test is unreliable. It gave you the exact same results twice. Did you do additional tests that did not return similar values? Or, did you foul a number of the test?
I'm impressed with your dedication to this! And yes, your salt is whacked (for IO). It is testing much more like Reef Crystals. And, in that case, I'm wondering why the heck I'm paying for Reef Crystals when the plain IO is returning results like that.
I wasn't able to pick up the Hanna Checker and the Elos Calcium test last night, as I narrowly missed Dave @ Concept. I'll be picking those up tonight. And, I will endeavour to get some numbers that corroborate. Once I have numbers I trust, I'll have a better idea how to approach this.
Did another 10% wc last night . . . and my euphyllia are ****ed! I'll be spying on them with the ip cam today. They all shrunk right up into their skeletons.