I could have sworn there used to be a thread of how to copy the ratios of Bot. Cal Mag+, I can't seem to find it anywhere.
I'm going through 10+ gallons a month and its driving me bonkers.
I was planning on Cal-Nitrate from JR Peters, Epson Salts, and some MOST by JR Peters...
Does botanicare have micros? Magnesium nitrate, cal nitrate and iron chelate(dtpa or eddha).....should get you there...exact ratios are in one of the diy threads...maybe dankworths
I plan on switching over to making my own base and boosters but I am too timid to make the switch just yet. I typically keep the mentality, if it ain't broke don't fix it, and can't afford any mistakes in my bigger rooms, 60k total. I typically keep all my tests and trials in my smaller test room.
But I figure making my own Cal-Mag is a start and should be a simple one at that.
You would think this would be pretty simple to do; however, when I got to looking into things a bit, there are some oddities.
The first, smallest and easiest variable to cover is the density. The post that OGsus referenced, shows a density of 1.0208. The bottle that I have of the product can be figured 2 ways (metric or US) and comes out to either 1.02666 or 1.03125.
Calculating a 10 ml/Gallon dose of the cal-mag and using either extremes for density; we come to a variable of;
1.03125 @ 10ml = 54 - 33 - 87 - 2.72
1.0208 @ 10ml = 54 - 32 - 86 - 2.70
(difference is small here, but when re-creating a stock solution; it least should be in the mind)
So, then; where the oddities come into play is when we try to build up this formula as listed on the bottle. At the minimum, Sulfur is definitely in there and not listed. It is also possible that Chlorine is present too; depending on how accurate you consider the GA.
From the GA: 2% NO3 - 3.2% Ca - 1.2% Mg - 0.1% Fe
(lists: Magnesium Nitrate, Calcium Nitrate)
First and foremost here. Calcium nitrate compositions do not vary greatly and cannot actually equal a 2% NO3 to 3.2% Ca ratio (i.e. that would be 15% NO3 and 24% Ca) Second, if we were to further add Mg in a nitrate compound; this would increase the ratio between Nitrate and Calcium. So, there MUST be other compounds in the mix OR their guaranteed analysis is waaaaaay off.
If we start with the profile for the manufactured Cal-Mag plus, based on GA and considering 1 gallon (@ 1.03125 density) stock solution; we get,
20,418 ppm NO3 - 12,251 ppm Mg - 32,669 ppm Ca - 1,021 ppm Fe.
To make the same profile using only listed ingredients: MgNO3 and CaNO3 (along with edta Fe); we have to base on Fe,Mg and Ca levels and not base on NO3. Which produces;
40,696 ppm NO3 - 12,250 ppm Mg - 32,679 ppm Ca - 1,020 ppm Fe. (E.G - with only listed components...the Nitrate must be 4% instead of 2%)
Then if we further compare the MSDS; we find there is definitely sulfates. "INGREDIENTS: Sulfates and nitrates of calcium, magnesium.
If we include magnesium and calcium sulfates as ingredients; then the same profile for all elements CAN be hit.
20,394 ppm NO3 - 12,250 ppm Mg - 32,683 ppm Ca - 1,020 ppm Fe - 22,568 ppm S
The problem here is that Calcium Sulfates' solubility is poor in water and further reduced by magnesium sulfate. However, it is increased with Calcium Nitrate and can be greatly increased with HCL. IF they are using calcium sulfate for the extra calcium (above 2g per liter) then they must also have HCL, i.e. Chlorine in the mix.
Finally then, to avert considerations for solubility of calcium sulfate and to still come close to the GA; we are left with one profile.
26,659 ppm NO3 - 12,250 ppm Mg - 32,679 ppm Ca - 1,020 ppm Fe - 16,165 ppm S
Note though, that neither of the last 2 profiles contain Magnesium Nitrate. A small amount could be included in the last profile along with the addition of a small amount Calcium sulfate; to end up at the same point with less S. However, I'm not sure if that would be necessary.
---For my recommendation then, would be to use the last image above and dissolve : 651 gm Calcium Nitrate, 478 gm Magnesium Nitrate and 29.7 gm Iron EDTA - into 1 gallon.
This would equal, pretty much, the Mfg. version. (though Nitrate is 2.6% rather than 2% shown on label)
You would think this would be pretty simple to do; however, when I got to looking into things a bit, there are some oddities.
The first, smallest and easiest variable to cover is the density. The post that OGsus referenced, shows a density of 1.0208. The bottle that I have of the product can be figured 2 ways (metric or US) and comes out to either 1.02666 or 1.03125.
Calculating a 10 ml/Gallon dose of the cal-mag and using either extremes for density; we come to a variable of;
1.03125 @ 10ml = 54 - 33 - 87 - 2.72
1.0208 @ 10ml = 54 - 32 - 86 - 2.70
(difference is small here, but when re-creating a stock solution; it least should be in the mind)
So, then; where the oddities come into play is when we try to build up this formula as listed on the bottle. At the minimum, Sulfur is definitely in there and not listed. It is also possible that Chlorine is present too; depending on how accurate you consider the GA.
From the GA: 2% NO3 - 3.2% Ca - 1.2% Mg - 0.1% Fe
(lists: Magnesium Nitrate, Calcium Nitrate)
First and foremost here. Calcium nitrate compositions do not vary greatly and cannot actually equal a 2% NO3 to 3.2% Ca ratio (i.e. that would be 15% NO3 and 24% Ca) Second, if we were to further add Mg in a nitrate compound; this would increase the ratio between Nitrate and Calcium. So, there MUST be other compounds in the mix OR their guaranteed analysis is waaaaaay off.
If we start with the profile for the manufactured Cal-Mag plus, based on GA and considering 1 gallon (@ 1.03125 density) stock solution; we get, View attachment 489769
20,418 ppm NO3 - 12,251 ppm Mg - 32,669 ppm Ca - 1,021 ppm Fe.
To make the same profile using only listed ingredients: MgNO3 and CaNO3 (along with edta Fe); we have to base on Fe,Mg and Ca levels and not base on NO3. Which produces; View attachment 489770
40,696 ppm NO3 - 12,250 ppm Mg - 32,679 ppm Ca - 1,020 ppm Fe. (E.G - with only listed components...the Nitrate must be 4% instead of 2%)
Then if we further compare the MSDS; we find there is definitely sulfates. "INGREDIENTS: Sulfates and nitrates of calcium, magnesium.
If we include magnesium and calcium sulfates as ingredients; then the same profile for all elements CAN be hit. View attachment 489772
20,394 ppm NO3 - 12,250 ppm Mg - 32,683 ppm Ca - 1,020 ppm Fe - 22,568 ppm S
The problem here is that Calcium Sulfates' solubility is poor in water and further reduced by magnesium sulfate. However, it is increased with Calcium Nitrate and can be greatly increased with HCL. IF they are using calcium sulfate for the extra calcium (above 2g per liter) then they must also have HCL, i.e. Chlorine in the mix.
Finally then, to avert considerations for solubility of calcium sulfate and to still come close to the GA; we are left with one profile. View attachment 489773
26,659 ppm NO3 - 12,250 ppm Mg - 32,679 ppm Ca - 1,020 ppm Fe - 16,165 ppm S
Note though, that neither of the last 2 profiles contain Magnesium Nitrate. A small amount could be included in the last profile along with the addition of a small amount Calcium sulfate; to end up at the same point with less S. However, I'm not sure if that would be necessary.
---For my recommendation then, would be to use the last image above and dissolve : 651 gm Calcium Nitrate, 478 gm Magnesium Nitrate and 29.7 gm Iron EDTA - into 1 gallon.
This would equal, pretty much, the Mfg. version. (though Nitrate is 2.6% rather than 2% shown on label)
In reality, when you copy Calmag+ labeled concentrations of calcium and magnesium, using CaNO3 and MgNO3 you end up with closer to 4% nitrogen than 2%.
Attached is the hydrobuddy calculations for making one gallon of concentrate with the following label concentrations
Nitrogen
NO3: 3.8%
NH4: 0.1852%
total nitrogen: 3.985%
You can't put sulfate salts in concentrated solutions with calcium salts. Because you get calcium sulfate precipitate. Calcium sulfates max solubility is alittle over 9 grams per gallon of pure water(it goes down some in concentrated mixed solutions). This about 431 ppm sulfate(9 grams CaSO4 per gallon)
So if you include magnesium sulfate in the mixture, you should limit its use to about 430 ppm sulfate. Which will help bring the nitrogen numbers down a little, but imho is not worth the trouble or risk of precipitate. My advice would be to stick with magnesium nitrate and avoid magnesium sulfate in this situation.
The labeled guaranteed analysis is a minimum. So the real cal-mag plus is labeled at 2% but legally can be anything over 2% concentration nitrogen.
@Quantrill Doh! you made an excellent point there and my recommended version would indeed seem wrong / not likely.
When trying to resolve the huge gap in GA with NO3; I did look into saturations for Gypsum (and commented on it above) along with changes to saturation with Calcium nitrate, Magnesium nitrate, magnesium sulfate and HCL (others too I suppose not relevant). Then I also saw that the MSDS showed sulfates. Also, in that looking; I found Fatman's formula for Cal-mag which showed only the magnesium sulfate (instead of nitrate).
From that, I started looking at getting the NO3 down with Epsom instead of Gypsum......but......never even crossed my mind that the solubility would be the same even with different compounds. :eek:
Searching a bit more for fatman's formula just now; I did find one thread talking about precipitation. So, even given his status (past); it may very well not work. (suppose HCL possibly)
@Billyboat
It may be best then to either run the first shown profile above from me or either of Quantrills' profiles (@Quantrill could you post the GA for the compounds you used to keep ppms same?)
(I did also compare total nitrate when substituting either gypsum or epsom and considering saturation; either compound will net the same total N, so its' 6 with 1 and a half dozen to the other there.)
@Quantrill last, ye I'm aware that GA is a minimum; but since the minimum here shouldn't ever be even below 3.5%, I'm not sure how they got away with such a low rating! Maybe they've got some pretty poor quality control as I cannot think of any reason to ever be 2%.
I'd recommend against the consideration of HCL. Its not going to make miracles happen at the concentrations we are discussing. And keep studying if you consider fatman a resource.(not intended to be a jab at you, just the blunt truth as I see it.)
Regarding the discrepancy in the nitrogen from the GA, I have presumed it to be a marketing decision. They want this product to be a calcium and magnesium fertilizer in the consumers eye, not a nitrogen fertilizer. So they label at 2% and by legal label standards so long as they don't go below this concentration, it can have what ever concentration the chemical ingredients contribute to it.
But then again I have also read that it has other trace elements in it as well. Copper, boron, manganese, cobalt iirc. Though they do not list them in the GA. Which by my understanding of the labeling laws, is not legal. If you make a claim that the product has such and such plant nutrient in it, you have to give a guaranteed minimum analysis.
The GA of the ingredients I used in my calculations above are as follows:
Magnisal magnesium nitrate
NO3=11%
soluble magnesium=9.6%
Yea, the HCL was just to point out, but I didn't include any recommendations for safety here as I would prefer to test it myself. I suppose though, if we did use a 0.75% HCL solution; then we could raise the solubility of Gypsum to 24 g per gallon. Decent, but still not enough to fully augment with epsom or the like; though may drop NO3 a bit more. Again, I would want to test this first.
interesting point about choosing a lower level since the focus isn't on Nitrate. I suppose in connection to your following points; I know that certain elements (if not advertized per se) don't have to be listed. Many fertilizers have sulfur but don't list the % in the GA (typical commercial fert co's like MG and Cal-mag here); I assume since it was not considered essential for so long / is not being marketed as containing. Similarly, many commercial ferts have sodium compounds and never list those, but aren't considered usable, so they aren't listed. With the other traces in the Cal-mag; they are probably just impurities and again wouldn't have to be listed.
If I remember correctly from the fish store; Instant salt mix for aquariums have only 5 base ingredients, yet they list a whole slew of trace elements. In this case these are all also impurities, but since they are selling on being "complete" they list em. I thought that was funny to learn back then.
I too switch back to Magnesium Nitrate and Calcium Nitrate. General Hydro uses Calcium Carbonate, it works fine for awhile and then I think it builds up, creating lighter colored leaves no matter what you do. Botanicare goes cloudy and it's expensive. Thanks for the mass calculation Quantrill, I couldn't get Hydro Buddy to work for me. I see the EC, what ppm is this mix at 5ml?
I'm using Magnisal for Magnesium Nitrate and Haifa Calcium Nitrate, the ratios appear the same.
