There is no such thing as a "cal-mag" deficiency...

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Seamaiden

Seamaiden

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Thread title pretty much says it all. Use the charts in my signature line to help with understanding cal mag deficiency, but the gist of it is this: Calcium (Ca) and magnesium (Mg) are two different elements required for plant nutrition. One, Ca, is mostly immobile. That means it cannot easily be translocated (moved) through plant tissues. The other, Mg, is highly mobile in plant tissues.

Understanding cal mag deficiency is important on a few levels, including making a proper diagnosis. Because Ca is mostly immobile a deficiency will only occur on the upper, or newer growth. Because Mg is so mobile deficiencies occur on the older, or lower growth.

Their appearances and effects are also very different, and while both elements play together and are required by the plant, they cannot be lumped together as a single deficiency. You can experience both a Ca- and a Mg-, but they are not one and the same thing, not at all.

This is one of the charts posted in my thread, and while it is very good it does have a mistake--calcium is mostly immobile. Keep that in mind.

Best cannabis deficiency visual chart


BOTH Ca and Mg can be delivered into plant tissues via foliar applications to help correct, however, while the Mg- signs prior to actual necrosis can be alleviated and even reversed, the same cannot be said of Ca-.

In most cases these deficiencies are due to nutrient ratios, watering practices or environmental issues (such as PH, Temperature or Humidity) and adding more will not correct the issue. So the if you are seeing these issues you want to start looking closely in those areas to find and correct the root cause.
 
2hotmomma88

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I've been using this chart and I thought I had a Mag def. Some of my stems are purple but it's not in the veins of the leaves. Some of the new growth is a light green. I've also been reading about ph. Before I started adding lime I got a soul tester that tells ph and moisture. Best 13.00 I've spent thus far. Ph was around 5 and my soil is wet. I've been over watering. Can this be the cause of the deficiency?
 
MakinGoo

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Very interesting Sea..

But I think I have a CalMag deficiency.. im super late in flower & in mid bloom I ran out of CalMag so 4 a good chunk of bloom ive been running RO water with no added CalMag & im noticing very small rust spots on the top leafs.... I would of guessed that was a CalMag deficiency bcuz that usually happens 2 my calmag beast mode plants like True OG Kush that love calmag deep in flowering..

my leaf aint on the chart its nice & healthy green but with new rust spots<<<<Most OG Kush strains will do this late in bloom & I always thought they wanted more calmag..
 
caveman4.20

caveman4.20

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Cal and mag use eachother or need eachother to be ?properly? Absorbed maybe this is why they are commonly deficient at the same time....from the top of my head plant uses atleast 3x more calcium then magnesium...
 
Cort

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Think some are missing the point. Ill try to relate to the human body

You can be hungry, or your can be thirsty, and sometimes you are both at the same time. While you often eat and drink at the same time for convenience they each have their own signs when deficient.

Now again with plants. You can be deficient in Magnesium, or deficient in Calcium, sometimes both at the same time. While you often feed Cal and Mag at the same time for convenience, they each have their own signs when deficient.

At least this is my interpretation of what Sea is saying.
 
PButter

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You know, I just realized I've had the symptoms backwards for the last few months regarding Ca showing at top and visa versa... Whoops, thanks for posting again!
 
sixstring

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The thing is we always use the term calmag because thats how it is most commonly sold, pre packaged together. And im pretty sure scientists tell us to use them together because they work better that way.like it would be real easy to overload the plant with calcium if there was a lack of magnesium in the plant or medium.
I still lol every time I see a newbie post a problem and the first response is calmag deficiency without much grow info to go off :)
 
Natural

Natural

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Nice post SM! I love the dichotomy presented here.
People should not read into this as "no need for calcium or magnesium" though..lol.
Balance in the soil, balance in your nutrient solution, and a balance in PH are all very important aspects of growing plants. As is soil aeration, temps, and humidity all playing their part in what happens on a molecular level to the nutrients made available.

A little cut/paste blurb..that will help understand the "immobility" of Calcium uptake..

Mobility and Uptake of Calcium by Plants
Calcium uptake by the plant is passive and does not require energy input. Calcium mobility in the plant takes places mainly in the xylem, together with water. Therefore calcium uptake is directly related to the plant transpiration rate.
Conditions of high humidity, cold and a low transpiration rates may result in calcium deficiency. Salinity buildup might also cause calcium deficiency because it decreases the water uptake by the plant.
Since calcium mobility in plants is limited, calcium deficiency will appear in younger leaves (die back or burns) and in fruits (blossom end rot, bitter pit), because they have a very low transpiration rate. Therefore, it is necessary to have a constant supply of calcium for continued growth.


Organic growers who use Humates are going to have very little problems with CEC, most likely it would be a PH issue(might include a liming issue). Those of us who use strictly salts in soil, might consider adding Humates to their medium. The positive ions of Sodium will compete with Cal+ and Mag+ ions..over-all I think the ratio issue is over-emphasized, unless that ratio exceeds 25:1, as the plant will uptake what it needs, if the availability is there. Taking this into consideration, in a high salinity nutrient diet..I would consider applying Ca to the soil and Magnesium as a foliar..or some variation of this technique depending upon your needs. This might help the competition between the positive cations of Calcium, Magnesium, and Phosphates; especially at the flower stage.
 
Natural

Natural

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Very interesting Sea..

But I think I have a CalMag deficiency.. im super late in flower & in mid bloom I ran out of CalMag so 4 a good chunk of bloom ive been running RO water with no added CalMag & im noticing very small rust spots on the top leafs.... I would of guessed that was a CalMag deficiency bcuz that usually happens 2 my calmag beast mode plants like True OG Kush that love calmag deep in flowering..

my leaf aint on the chart its nice & healthy green but with new rust spots<<<<Most OG Kush strains will do this late in bloom & I always thought they wanted more calmag..

Goo..I think mainly, she is supporting the theory of people having a Calcium deficiency or Magnesium deficiency rather than both at the same time..more or less to draw a line. Although, I don't think it is impossible to have both deficiencies at the same time though. And her point, is definitely not that plants do not require Cal or Mag, but more to the point that every deficiency shown is not always a Cal or Mag deficiency, but more to the point it could be another nutrient lacking or over applied.
I would get some more Cal-Mag and have it on hand, especially for RO and especially for OG.
 
Smoking Gun

Smoking Gun

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I think another point of this is that having a single CalMag product is not always the best solution. Having both calcium and magnesium in feeding regiments and soil blends as they are essential for the function of plant growth. Some companies have begun producing independent calcium and magnesium products and these may be more efficient solutions for the individual imbalances experienced; at least this provides the ability to give more exacting amounts of each element.
 
Smoking Gun

Smoking Gun

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the cal-mag craze started maybe 5-10 years ago.. I think giving your plants cal-mag can help create issues & deficiencies ,.. I never owned or used cal-mag supps in over 20years but been around enough grows and plants to say most plants don't need it as much as people think they do :blackalien:

This is on the right track, but not quite there. Cannabis absolutely needs both calcium and magnesium for the essential functions of their life cycle. In fact Cannabis can use almost as much calcium as the other macronuntrients whereas magnesium is not used in the same ratios. Calcium is vital in the movement of other nutrient molecules through the plant cells and tissues and for the integrity of cell structure. Magnesium is absolutely essential for the production of chlorophyll as it is the central molecule used in the formation process. So it is clear that both of these elements are essential for the best possible results from our plants. However it is the idea of applying the two together that may be the issue. (I personally feel that the reason CalMag products were produced as they were because the discovery of their importance in hydroponic systems was discerned at approximately the same time. So nutrient producers simply put them in the same bottle). Reaching toxic levels of calcium is easy to do, especially in soil. A toxicity of calcium will prevent other nutrients from being absorbed by the plants roots properly, so this issue may be misidentified as deficiencies of other nutrients. This to me is the main issue with adding calcium, it may quickly become too much around the root zone. Toxicity of magnesium is much less common, but if one is seen it will also likely react with calcium creating more problems. But deficiencies of Mg is not wholly uncommon but easily remedied with epsom salt or another magnesium supplement.

So while we can see that having both elements in the nutrient profiles being provided to the plants applying them together may in fact be an issue. As I said above using the products that separate calcium and magnesium is probably the best option for providing plants with both of these elements. The two elements may in fact react with each other, but potentially with negative consequences. This makes it essential to have both elements available in whatever is feeding our plants, whether it is the soil or a nutrient solution, but in proper proportion to one another, which is approximately 5:1 (Ca:Mg).

GhostFace, you likely have not had to use the CalMag additives because you are growing in a medium that has enough of each element available. The other option is that you use nutrients with a proper balance of the two elements. But one way or another you are providing these elements to your plants in an amount they can handle.

One other thing to take note of is that zinc deficiencies look very similar to magnesium deficiencies. So if you feel as though you are providing enough magnesium to your plants you may want to examine the levels of zinc in your feed or medium.
 
sixstring

sixstring

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This is on the right track, but not quite there. Cannabis absolutely needs both calcium and magnesium for the essential functions of their life cycle. In fact Cannabis can use almost as much calcium as the other macronuntrients whereas magnesium is not used in the same ratios. Calcium is vital in the movement of other nutrient molecules through the plant cells and tissues and for the integrity of cell structure. Magnesium is absolutely essential for the production of chlorophyll as it is the central molecule used in the formation process. So it is clear that both of these elements are essential for the best possible results from our plants. However it is the idea of applying the two together that may be the issue. (I personally feel that the reason CalMag products were produced as they were because the discovery of their importance in hydroponic systems was discerned at approximately the same time. So nutrient producers simply put them in the same bottle). Reaching toxic levels of calcium is easy to do, especially in soil. A toxicity of calcium will prevent other nutrients from being absorbed by the plants roots properly, so this issue may be misidentified as deficiencies of other nutrients. This to me is the main issue with adding calcium, it may quickly become too much around the root zone. Toxicity of magnesium is much less common, but if one is seen it will also likely react with calcium creating more problems. But deficiencies of Mg is not wholly uncommon but easily remedied with epsom salt or another magnesium supplement.

So while we can see that having both elements in the nutrient profiles being provided to the plants applying them together may in fact be an issue. As I said above using the products that separate calcium and magnesium is probably the best option for providing plants with both of these elements. The two elements may in fact react with each other, but potentially with negative consequences. This makes it essential to have both elements available in whatever is feeding our plants, whether it is the soil or a nutrient solution, but in proper proportion to one another, which is approximately 5:1 (Ca:Mg).

GhostFace, you likely have not had to use the CalMag additives because you are growing in a medium that has enough of each element available. The other option is that you use nutrients with a proper balance of the two elements. But one way or another you are providing these elements to your plants in an amount they can handle.

One other thing to take note of is that zinc deficiencies look very similar to magnesium deficiencies. So if you feel as though you are providing enough magnesium to your plants you may want to examine the levels of zinc in your feed or medium.
i cannot agree on calcium being essential to weed growing after using jacks classics for months and never adding cal or mag to my plants.i run promix/coco with r/o water and im telling ya other than 1 or 2 plants that looked like they needed some help i never used the stuff on anythingand after those plants were gone i went months without needing calmag on anything.i just started feeding heavy on stuff that looked def and they pulled through fine.the jacks has plenty of mag but not a drop of calcium.so i would say the ratio for healthy plants is 1 to 100 cal to mag.theres something about the jacks classics that must balance shit out,maybe iron or zinc levels.but im back using ionic and a/n and i been forced to use calmag almost weekly again.
 
caveman4.20

caveman4.20

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Plants must make some of their own calcium or perhaps their some atmospheric calcium available to plants......
 
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