Cal-Mag at beginning of grow cycle

I have quick question. I have autoflowers in 50%-50% fox farms and Nectar of Gods(super soil. ( super soil( Diagnosed a couple bottom leaves on 2 plants with calcium deficiency. Small red dots. This was after about 3 weeks. I’ve been told those soils need no additives until 4-5 weeks.Should I have been using Cal-Mag plus from beginning with PH adjustment? Plants telling me yes….Thanks Richard ( watering with spring water very low TDS if any)


Most plants won’t need cal/mag until you get near flowering. It’s unlikely you have a deficiency at this point. That said, added cal/mag isn’t going to hurt the plant, as I don’t think that I’ve ever seen a cal/mag excess. Add some it it makes you feel better, but don’t overdo it.

I have never added cal/mag until flowering in FF soils and have never had a problem, nor do we often see problems with cal/mag this early in a grow.


I’ve always added Cal/Mag early on… before actual nutrients. I have one that is 0-1-0

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I had small red spots on bottom leaves. Pictures I matched up dictated calcium deficiency. Watering with spring water(dead water) this was after 3 weeks of this grow. Started adding cal-mag into water, also second night of spraying with cal-mag (3teaspoons per gallon) looks like stopped leave problem, thanks….Richard….

Nice. Most calmag is a 1(2/5) - 0 - 0. Who makes the phosphorus calmag?

Sorry, It’s 1-0-0


Mendocino Flowering Cal Mag


I was using Fox Farms bottom 50%, Nectar of Gods (super soil ) top 50%. Hydroponic store told me didn’t need any supplements for 4-5 weeks at least. Noticed small red spots bottom leaves. Looking at pictures of leave problems diagnosed as a calcium deficiency problem. Started putting Cal-Mag plus in water 2-0-0 at 6.2 ph. Also mixed 3 teaspoons of Cal-Mag in spray bottle and have been spraying on leaves at night after lights go out. This solved problem and invigorated all leaves. They love spray. Hope info helps others.