Can I use Cal Mag with Fox Farms Trio?

If so, do I use them mixed together or by itself? Thanks…

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You can, I use GH and they advise adding cal mag before any base nutes. If using silica; silica first then cal mag. I normally only give it during water-only days but that’s just me.


Could you explain to me the value of using Cal Mag please? I have read about its use and was wondering when to use, during the entire grow, and how much? thanks :rofl:

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I’m trying to figure out the same thing. From what I’ve read it supposed to help with plant deficiencies. I would like to know for sure though.

Indoor growing with high intensity lights causes increased demand for calcium. This supplements that. If plant is experiencing a deficiency usually cal mag is the treatment.


Thanks, when do you advise to use it. I have read than some supplement when they only water, but do you make it a regular item, and how can you tell your plant needs cal mag?

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If you see a deficiency starting, use a chart to determine what it is. If it’s calcium or magnesium then add cal mag per package requirements. Some growers just go ahead and add it. It won’t hurt the plant. I normally dose plant on water only days. Outdoors in-ground normally not necessary.

Thanks that is what is so great about this forum. Experienced growers willing to help others. this hit for you :rofl: :bat:


Thank you for contacting FoxFarm! I would be happy to help.

Yes, you can use BushDoctor Cal-Mag together with our Soil Trio products; Grow Big , Big Bloom and Tiger Bloom . I received this email form FF. Mine is not the Bushdoctor, but I’m assuming regular Cal Mag is pretty much the same thing.