When calcification occurs, that is either corals growing their hard skeletons, coralline algae growing or abiotic precipitation, there is a defined amount of calcium, alk
and mag used in this process. For every 2ppm mag used, there is aprox 18ppm calcium and 2.7 dKH alk
If your mag was 1100 and is now 950 (drop of 150 ppm
), that would mean your calcium has dropped 1350 ppm
and your alk
. Obviously there isn't that much calcium or alk
in the water column which would tell me either your test kits are bad (or you are reading the results incorrectly) or you did alot of water changes with salt very low in all 3 elements.