The problem with the plants seems to be a magnesium deficiency. Will epsom salt harm soil microbes(bacteria, fungi, mycorhizi). Ive been reading alot about the soil foodweb and am concerned that because Epsom salt is a salt it has the potential to harm soil microbes. What about the sulphur in epsom salt? Why is not ok to use sulphured molasses but its ok to use epsom salt which contains sulpur for magnesium deficiencies? The concern for all this stems from reading that calmag plus contains iron edta which is apparently not organic and not good for soil life. Being im using RO water i had intended to use the calmag to remineralize the water for waterings but like usual the plan has changed mid grow. Im looking for a replacement for these minerals. I have well water that stinks and I will not use it on my plants its ppm is about 400. Even the tap in the area is hard as hell and its an inconvenience, We can get RO water a quarter a gallon put thru a 5 step RO filter so that is the cheapest most consistent source. What I started doing was using RO water to make casting tea with some ancient forest and the occasional molasses and testing the water and to balance out at .3 EC 200 ppm on my hanna meter for waterings. I figure this leaves me at the same spot EC wise for waterings as the calmag and the water is much more alive and with the castings should have a decent aray of nutrients for plant growth. But my magnesium levels and calcium levels are up in the air is it safe to use epsom salt and molasses to cover any deficiencys that do come about?