CALMAG for plants

[boats4906]

Has anyone use calmag for their garden and is it harmful to the fish? I have been spraying the leaves of the plants. 

thank you

james

[Vlad Jovanovic]

calmag is a generic term for "calcium-magnesium"... as far as whether it will be effective as a foliar feed will really, really depend on what "versions" of calcium and magnesium the manufacturer chose to use create his product. Some forms of cal-mag would be totally useless as a foliar leaf spray. For instance cal-mag as calcium carbonate and magnesium carbonate, two items that make up dolomitic lime. They are also the two items most abundantly found in tap water. Those two are where the gist of the digits come from on your EC or TDS meter's display, when you test your tap water. That is, if you don't have soft, low pH, aggressive tap water (most people don't...a few probably do). Again, they are useless in those large molecule, clunky carbonate forms (they of course can be made to be plant bio-available, but that would go beyond the scope of this already long winded reply)...

Now, some manufacturers who use any of the below forms of calcium-magnesium:

* Calcium Nitrate
* Calcium Carbonate
* Calcium Chloride
* Calcium Gluconate
* Calcium Proteinate
* Calcium Acetate
* Magnesium Nitrate
* Magnesium Carbonate

Beyond these there are manufacturers who chose to use a syntheically chelated form of Ca-Mg. Most typical chelating agents used are a class of poly-amino carboxylic acids such as ETDA, DTPA, or EDDHA. (In order from worst/cheapest/least effective - to - best/most expensive/most effective...with DTPA being in the middle of the road). 

And lastly, there are some manufacturers/brands of cal-mag that have been non-synthetically chelated with living microbial biology, and are in a form that is more readily available to your plants. These types of cal-mag can actually be foliar sprayed on the leaves and absorbed in a matter of hours. Results can sometimes be seen amazingly fast and deficiency problems can be corrected in a matter of days. Anyone who has tried some of the more "classic" hydro approaches in the past knows that  Ca or Mg deficiencies can sometimes be difficult to correct.

Also, it would be prudent whenever foliar feeding to use some type of anti-fungal protection, since most fungal pathogens require free water on the leaf surface to infect your plant. So wetting the leaves is a bad idea without protection. Since it's AP... the usual anti-fungal suspects like copper (Cu), manganese (Mn), zinc (Zn), or any any anti-fungal dithiocarbamates are out of the question.

While things like potassium bicarbonate (KHCO3)...or even sodium bicarbonate (NaHCO3...i.e baking soda) are totally AP appropriate chemicals to use as an anti-fungal foliar component, or a pH buffer. (I hope we can all cut the crap about the term "chemicals" being a dirty word. When broken down, everything is a chemical. I happen to like Methyl 2-hydroxybenzoate in my tea. Methyl 2-hydroxybenzoate is found inside the mint leaf and is what gives mint leaves their minty flavor. Methyl 2-hydroxybenzoate despite the somewhat scary sounding name is just what folks call mint).

Some are chemicals are great, healthy and appropriate, some are horrible choices (I'm not picking on anyone in particular at all or anything like that, it just seems like there is this on going trend in AP-Land to only use the word "chemical" in a negative context for some reason)...but anyways...

For some time now, in a 'just for the heck of it' effort to try and get away from (even the AP, or Organic gardening appropriate ones) chemical substance, as of late I've been using different biological anti-fungal components in my various foliar sprays. Most significantly in this regard is culture of  <4% of Bacillus subtillis which is then dilluted to 0.5% to 1%. This seems to be working as well or better than using freshly brewed worm castings, since worm teas biological content and effectiveness seems somewhat dependent on the brewers 'skill' or methods.

But combining the two, and innoculating my worm teas with the Russian B. subtillis recipe has been a grand idea me thinks. So far, no problems either in the AP GH, or with any of the 600 or so plants out in the organic garden or in any of the various 'trial' fruit trees with any type of fungal pathogens. You folks in the US might try a product like "Actinovate" the active ingredient is not specifically B.subtillis, but something very, very similar...Keep in mind these wont chelate your cal-mag, or anything like that. They will only give a form of protection against fungal pathogens while spraying.

Like Randall mentioned there are some other (non foliar) ways to add both Mg or Ca. Some will effect pH, others wont depending on what you want/need.

Hope some of this helps if nothing else, then in a general sort of way...but you'll need to be more specific about what 'form' of cal-mag the maker of your particular product used in order for anybody to give you any meaningful answer to you question(s). In addition to "is it harmful to fish"?, I'd also ask myself "how effective is it for my plants"? 

[boats4906]

About the exact type of calmag that I have in question is called CaMg+ ( calcium magnesium supplement ) by General Organics