All that sounds great, Dawn! Smart. Glad to hear there were no surprises! I like how you weighed the test results, with your inverts' health, and then decided your course. That sounds to me that you are experienced and intuitive enough to 'make the call'. Testing confirms it.
That's interesting, your magnesium consumption. I've dosed it in the past, but never noticed its effect. Not like iron, which I often do see its effect. I'll have to make more of an effort to see it. Good to know!
I suspect that in some cases, macro will utilize calcium & magnesium in the ratios that they are in the water, but I am just guessing. Yes to iron having most obvious change in macro apereance like darker green or red color. I think that Dawn has a "œgreen thumb, when it comes to seaweeds.
Michael, I am happy to see your build thread in motion. Keep it coming.
Dawn, as always, have a blessed day. Better, "œSeize the Day".