..what's this Ca-Mg product you have? Don't sweat the "organic" part of such a supplement, frankly it's technically BS, even if it's derived from rock CaCO3,.. such a substance simply doesn't fit into the definition of "organic", and the plant doesn't give f*ck-all either way... All the nute ions regardless of their original source(organic/synthetic) get into the plant in the same limited type of forms....nitrate is nitrate to the plant, Ca++ is Ca++, etc.... limited use of synthetic nutes isn't going to queer a damn thing, I use a blend of both and am getting the best results to date! Most of the troubles with synthetics is overfert'ing, screwing up the osmotic balance in the medium, around the roots, low pH, and in some cases the plant taking up too much, past what (mobile) nutes it can store for later use, and that not getting tapped out by harvest,.... Ca and Mg are secondary nutes, needed all the time in significant quantities; with your weirdly soft tap water (are you sure about that EC/TDS reading on it?), some Ca-Mg is needed at least 1-2x weekly,... Most supp's are at least in part carbonate based, and often also with nitrate (1-0-0, 3-0-0, etc) as well, but it's the carbonate/bicarbonate anions that are involved with pH buffering....
In the future, I highly recommend you using a dedicated micronutrient supplement, Bloom has one I believe,.. and use humic-fulvics, very good for both plant and microbes (Reference section has a great article on this).....carbon source for 'crobes, chelation of nute ions, etc.,.... critical for micronutes, as they are usually metal ions, bloody reactive unless "protected" by chelating agent that form a matrix around the ion, not literally bonding with it, but neutralizing the charge and blocking access of other cross reactive ions and cause formation of unavailable compounds,... Micro's play huge, critical roles as catalysts, metabolic agents, etc.,...
fooooooock,....!
