Oyster Shell Question

[Rick]

Calcium Nitrate will form CalCarbonate in the presence of Ammonia but I'm not sure the conversion will happen at the low concentrations in the media

This is new on me.

Calcium carbonate as formed when free calcium ion is in a high pH solution so CO2 converts to bicarbonate and then carbonate ion. Calcium carbonate (limestone) is the solid precipitate in the process.

In a pot pH is rarely high enough for limestone formation. Typically we see the converse that the pot is an acidic system that dissolves limestone and releases CO2.

Nitrate ion is converted to N2 gas by anaerobic bacteria and will release bicarbonate ion in the process, but if the predominant pH system is low, then it just gets changed to CO2 and gasses off.

Ammonia is converted to nitrate by aerobic nitrifying bacteria. This is a bicarbonate consuming process.

So under typical pot conditions, you don't get limestone formation with fertilizer application.

 

[gonewild]

The conversion could only happen under a controlled system with ammonia and CO2 gas so maybe I did not say exactly what I meant. I'm remembering a lecture I heard about how fertilizers are made (years ago).
So the correct answer is it could not happen in a pot of media with living plant roots.