So, you're saying that you've noticed this very same issue yourself?...I use 100% RO water, and am in DWC so both mine and your plants are far more prone to cal/mag deficiency than soil growers. But even at that, I've grown for 5 years under HPS with very few true calcium or magnesium defs...then within the first 2 weeks of growing under CMH, I encounter a horrible one. I still love my cmh though. If I must supplement with calmag during it's use, then so be it, it is worth the results. So, you remeidied your issue by running label strength calmag?...I also use Calimagic. Thanks for your answer Eastwood