Is the idea of the Antagonism relationships as new as that or is it that they are only recently gaining traction?
These things come in waves. Currently, here on TPT, there is strong interest in the possibility, but it is mostly based upon anecdotal evidence as well as studies of terrestrial plants. My opinion is that there is something to it, but I don’t know how much or if the terrestrial studies can be so readily applied to hydroponics.
I am not sure if this chemistry is correct but for what it is worth:
For calcium carbonate there is only a weak bond between the carbonate and calcium. Calcium would rather be bonded with chloride, sulfate, or nitrate Ion. So whenever possible calcium will react with with another sulfate imolecule resulting in Calcium sulfate and a a new carbonate molecule.
Since most of the ingredients used in micro mixes consists of manganese, zinc, copper, manganese sulfates, many of the micros might be converted to carbonates which may not be soluble. So if this guess is correct calcium carbonate may reduce the effectiveness of micro ingredients. It is only a guess and I don't know how to confirm it.
These is one atom in fertilizer that is more reactive than calcium. The atom is potassium. Magnesium is similar to calcium but it is slightly less reactive.
As to why GH boosters have so much potassium I don't know. But it is curious that GH boosters also have way more sulfur than necessary, for plant growth. Normally plants need about one sulfur atom for each phosphorous atom they need. From my own observations if the aquarium has no KH a GH booster will make the water acidic (PH of less than 6). But if your water has Some KH the excess sulfate will reduce KH. Possibly preserving the micro nutrients.
I was told the process was pH dependant and with the fluctuation of pH with CO2 injection the natural moderation is interrupted. This, as I was told, would result in more Ca and Mg than is anticipated. So perhaps not a bad way to go with low tech tanks but problematic with high tech.
Someone please correct me if I'm wrong.
Take a glass OF carbonated water. Measure the KH and GH and record the readings. Then add some dolomite. and let it sit. A day later come back and remeasure GH and KH, They will be higher than they originally were. The same will happen with magnesium carbonate or calcium carbonate.