Diy calcium magnesium suppliment - calmag

Southernontariogrower

Well-Known Member
I used to use GH calimagic, or Botanicare CalMg with my reverse osmosis water, for deficiencies but it was getting real expensive, so I searched for alternatives. I can't vouch exactly for the science behind what I did, but I can verify that my plants didn't die, and they also seemed to not have Cal or MG deficiency.

Basically I took information from various people who have already done similar, and somewhat modified it in different ways. Basically the major brands of nutrients based on their bottle labeling got their calcium and magnesium from things I had trouble finding, or seemed too dangerous for me to want to have mailed to my house. The major brands of Cal/Mag supplements have Calcium/Magnesium/iron chelate. So I'll tell you whats in mine, how much to use, and why I chose the amounts. I mixed the chemicals with my own RO water. The qtys that I purchased could make like 100+ gallons I think.

Magnesium Sulfate (Epsom Salts) - This can be purchased online, but I bought it from CVS for like $2. You can find it in many drug stores and stuff, it's considered a plant nutrient on its own, and it's used as bath salts and other things.

Calcium Nitrate - I purchased this on eBay. I got 5lbs of it for $14.00, and turns out I bought way too much. Primarily a fertilizer additive though it has some other uses. Seemed pretty harmless to buy online, and was easy to find.

Chelated Iron - Iron EDTA - This guy I don't know much about. I found some on eBay for like $15, though I've seen it in many forms. The one I used was actually a powder. I think the powder is for commercial sized fields of vegetable crops, but someone had made tiny packages of it to sell on eBay. I think the nutrient companies are selling water soluble iron chelate with nitrogen now, which would probably be what I buy next time.

Now to figure out the proportions I used an old formula by "FATMAN" from a different message board and plugged it into Hydrobuddy a nutrient calculator to figure out the weights. The one problem is that the PPM vs the Weights FATMAN recommended didn't match. So I basically just plugged his PPMs into HydroBuddy, and used those weights to make my mixture.

fatmans Cal-Mag

PPM
Nitrogen 200
Magnesium 120
Calcium 259
Sulfur 160
Iron 10.00

I plug these PPMs into HydroBuddy and the results it gives me are so:

Magnesium 120ppm
Calcium 259ppm
Sulfur 160ppm
Iron 10.00ppm


Per 1 Gallon of water:
IRON EDTA : .291 grams
Calcium Nitrate: 5.8 grams
Magnesium Sulfate: 4.607

Please note that these amounts are pretty tiny. I used a pretty accurate scale for this and made a gallon. Next time I plan to make a 5 gallon batch. I feel like it could be more accurate if I could work with larger qtys of these chemicals. Another side note, mixing Calcium nitrate and Magnesium Sulfate is supposed to create Gypsum. So I made sure to completely dissolve my Calcium nitrate in my gallon of water before adding the Magnesium Sulfate or Iron Chelate.

I am not a scientist, and I honestly don't know how to work Hydrobuddy that well. I have been growing for some years now, though I don't consider myself a grand master or anything. I did go through 1 gallon of this mix with a fairly large crop. I used approx 1 teaspoon per gallon of water with my regular nutrient schedule. (I use General Hydro 3 part + some supplements). I added this CalMag mixture at least 70% of the time that I watered. I would normally just add it every time, especially since its so cheap, but sometimes I was in a real hurry or something or paranoid about my experimental mixture.

I can't give you a guaranteed analysis or anything, but I can tell you this. My plants grew pretty much the same as if I had been still feeding the name brand CalMag. And my plants didn't seem to have deficiency in Calcium or Magnesium. I'm making some more, and I'm going to keep using it. I'll post if something changes, but I would love to hear input from people smarter than me.



Cheaper to use tapwater and some epsomsalt, lmo! But lm cheap f er.
 

VolimPicke

Well-Known Member
NP. It crazy how a simple remark about native traditions brings out the historians that feel they just have to school the natives.
In post #58 OldMedUser said nothing racist or derogatory to you.

In his comment, he merely made statements of fact and nothing derogatory.
So I do not understand why you went on the "White-splaining" comment that is racist.

We all know that "man-splaining" is feminist B S.
Do you like it when women use the term man-splaining towards you?
 

Tangerine_

Well-Known Member
In post #58 OldMedUser said nothing racist or derogatory to you.

In his comment, he merely made statements of fact and nothing derogatory.
So I do not understand why you went on the "White-splaining" comment that is racist.

We all know that "man-splaining" is feminist B S.
Do you like it when women use the term man-splaining towards you?
Simple. It was unnecessary to zero in on that one remark in an attempt to give credit to colonizers...especially under the guise of a history lesson.
And FTR, I've read enough of OldMedUsers posts in the politics section to know he's not a racist. The OP made a simple, short remark about a cultural tradition that is very old and it was jerkish to attempt to trivialize it.

Please dont respond to me in this thread. Its gone off topic enough. Start a new thread in the appropriate sub forum. The majority of your retort belongs in the politic section.
See ya there ;-)
 
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ledcflgrow

Well-Known Member
Magnesium Nitrate: 473.171 Grams

fe DTPA 10% or 11%: 37.854 Grams

Calcium Nitrate: 637.543 Grams

1 gallon Reverse Osmosis water

Nitrogen
NO3: 3.8%
NH4: 0.1852%
total nitrogen: 3.985%

Calcium: 3.2%
Magnesium: 1.2%
Iron: 0.1%
Unless I am getting something very wrong, this is like 5x more concentrated than calmag plus by Botanicare. This would add 2.5 extra pounds of weight to a gallon of water, which weighs 8.34 pounds. So this would make the net weight 8.34 + 2.5 = 10.84 pounds. However, their 1 gal bottle says net weight of 8.81 pounds.

I believe to get the grams of say Calcium in their product of 3.2% you do .032 x their net weight 8.81= 0.281 pounds, which is 127 grams.
 

ledcflgrow

Well-Known Member
Oh, never mind, duh. Calcium Nitrate is only 19% calcium, so you have to use about 5x more to reach the 3.2%. The extra weight must be accounted for by displacing water.
 

PeatPhreak

Well-Known Member
My favorite "calmag" contains no mag. It's Calcium EDTA. Works awesome for fixing or preventing a calcium deficiency with a foliar application.

Not good to use in the media. Foliar only. Not good to mix with other nutes.
 

Milky Weed

Well-Known Member
My favorite "calmag" contains no mag. It's Calcium EDTA. Works awesome for fixing or preventing a calcium deficiency with a foliar application.

Not good to use in the media. Foliar only. Not good to mix with other nutes.
Now you have me thinking… why wouldn’t chelated calcium work in irrigation solution? It sounds fucking fantastic. Would the chelation not keep it from binding to other elements in a weak solution?
 

Milky Weed

Well-Known Member
Can i add epsom salts to my nutrient mix without issues?
Canna A+B
Yes. Just combine separately, like don’t mix all the dry powders together then throw them in. I liked to get my water bucket swirling before I added nutes so they dispersed quickly but that’s probably not needed.
 

Star Dog

Well-Known Member
That’s what I did, started light and slowly increased until healthy.
It's not the best picture but they're looking a bit off, check the back left lower leaves.
_20211218_152636.JPG
since feeding the pot epsom at 0.2ec I can see a difference in the color of green with that lush healthy look back.
Eta... And the general overall look of them isn't great.
 
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Milky Weed

Well-Known Member
It's not the best picture but they're looking a bit off, check the back left lower leaves.
View attachment 5049496
since feeding the pot epsom at 0.2ec I can see a difference in the color of green with that lush healthy look back.
Eta... And the general overall look of them isn't great.
I feel you man. I’m always playing with nute levels it seems as my humidity changes or the temp changes. It’s hard tuning it in when your trying to push the light even alittle bit in my experience.
 
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