I've never used calmag in my life in either coco, hydro, or soil. If you are using decent nutrients they will already have plenty and then if you're using tap water there will be even more.
Calmag is the most overused additive out there. These days people just assume they need it. More often than not they don't. The goto remedy seems to be to add calmag regardless of what the actual problem is. Too much Ca and Mg can be detrimental and cause issues with other nutrients and the availability of the plant to access them.
I don't understand how in the past few years all these growers are growing in conditions that are lacking Ca and Mg. I don't think they are. It's more they see others using it so they just assume they need it. Kind of like those dumping high P/K boosters on their plants because they think they need it for bigger flowers. They don't and many actually reduce the yield and quality of their harvest by overfeeding their plants too much stuff.
You read these posts of someone with a young plant growing in soil and they talk about how they just started feeding calmag. It always amazes me. Why are people feeding a young plant just calmag? It makes no sense.
