I new there were smarter people. I hunted around and found these notes.
Magnesium is phloem mobile and readily trans-located within the plant to actively growing plant parts acting as sink (White and Broadley 2009. Consequently, due to the high
mobility under Mg starvation Mg deficiency symptoms typically appear on older leaves of the plant (Bergmann 1992).
Calcium is only xylem mobile, meaning it can only move up the plant, and once in place, it cannot be remobilized and moved to new developing tissues. Young developing tissues such as growing points and fruiting bodies tend to be affected the most once soil reserves are depleted.
Applying too much calcium and magnesium can cause a potassium deficiency; the K/Ca and K/Mg ratio should always be kept above 2 (but below 10, since
too much K can hinder the absorption of calcium and magnesium). Too much potassium can also prevent the absorption of certain micro-elements, such as zinc. It is particularly important to take account of this interaction when using
very hard water with a high calcium and magnesium content. (Bold italics are mine).
I just didn't want bigsublimefan to start throwing nutes in without looking at all the options. Looking out for each other. (Still think a little too much water

.
I handle my nutes by testing my water. I've learned the hard way by guessing what is happening to the plants. A leaf turning brown or yellow or curling can mean so many things. I'm just not a leaf whisperer.