Cal Mag?

Discussion in 'Growing Marijuana Indoors' started by Jaco55, Dec 21, 2022.

  1. Do I need to add Cal Mag to every feeding of a healthy Plant?
    OG Kush 4 weeks into flower planted in HF and OF soil mix using 3 liquid FF and 3 powder FF feeding once a week
    Or am I wasting the Cal Mag?
    How can I tell if/when a plant needs Cal Mag?
    Please advise
  2. Show pics, if you haven't used calmag then probably. I usually stop providing it during flower around week 3. Doesn't need calmag every watering. I'd generally use calmag on plain water days so i could give it a full serving without interfering with my regular nutrient ppms. Also depends what water you use when I use r/o I run into calmag issues since ro is mineral-less when I use tap I generally dont need calmag. Tap is different in different areas.
  3. I've been using Cal Mag once a week when I feed using FF feeding regime. rest of the time just distilled water
    So do I need to continue w/ the Cal Mag
    Here is the picture - healthy OG Kush - 4th week into 12/12
  4. Looks over watered, drooping
    Also see some burnt tips, not a big deal yet but signs of nutrient burn.

    I don't see anything resembling calcium or magnesium deficiency
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  5. looks over watered to me ?
    Why distilled water ?
  6. Watered 1/2 gallon today. Showing dry on my moisture meter. next feed on Thurs
    Distilled water because I have a big supply
    I live in the valley of the sun (Phoenix) and the tap water is full of chemicals
  7. #7 GroBuddy, Dec 21, 2022
    Last edited: Dec 21, 2022
    Those moisture meters are inaccurate, need to water off pots weight needs to be light with no water weight.

    I live in southern new mexico same here ppm of tap is 700-900ppm I water with tap ran through a boogie blue water hose filter.

    Google search calcium deficiency cannabis and magnesium deficiency cannabis easier to show instead of tell. Calcium you'll have rust dots generally starting towards the center of the leaf. Magnesium deficiency leaf veins will yellow and yellowing will grow from there.
  8. Overwatered and could do with a defoliation.
  9. If you are using distilled water I would add calmag to distilled water.
  10. If your water is reasonable then you can do what i do. I just dilute 1/2 with distilled water. I add Epsom salt at 1/4 teaspoon per gallon twice to prevent deficiency: once before flip and again during mid flower.

    Never used calmag ever. There's calcium already in the water and Epsom salt is practically free.
  11. Agreed. That's over water n SLIGHTLY over fed. Better than some of my old grows lol

    Sent from my SM-A536U using Grasscity Forum mobile app
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  12. R.o (reverse osmosis) water has a TDS # in the single digits. (Total dissolved solids) salt. Minerals etc.. tap water can reach a TDS of up to 350+

    Sent from my SM-A536U using Grasscity Forum mobile app
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  13. How many watts you pulling? Is that 2x2? Led?
  14. There is little to zero minerals in distilled water. bagged potting soil less soil is compost with normally zero dirt/soil in it.
    Dirt soil is where you get the minerals besides the minerals that is in well or city water.

    Also bagged potting retains water and can lead to what is called over watering which really its not the case.
    Its a lack of oxygen to the roots and sometimes leads to root rot.
    Its because tree bark and fern leaf's soak up more water then soil < ground up stone .

    Yes add Cal mag and zinc iron and DE Diatomaceous earth and keep your ph 6.0 to 6.5 .

    Roots need OXYGENATED WATER nutrients minerals at the right temperature and PH.

    IF your Hydroponic grower there is no such a thing as over watering.
  15. Yup. Im gonna go soil this time

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