Homemade cal mag How much ?how strong?

Tonycannavis

Tonycannavis

Well-Known Member
Today I made my first organic cal mag With the eggs vinegar The whole shebang my question is how do you determine the dosage ? And How strong it is ?don’t wanna mess up my plants Didn’t really read much about how much to feed on anybody done it before ? Any pointers appreciate it
 
cannabineer

cannabineer

Ursus marijanus
Tonycannavis said:
Today I made my first organic cal mag With the eggs vinegar The whole shebang my question is how do you determine the dosage ? And How strong it is ?don’t wanna mess up my plants Didn’t really read much about how much to feed on anybody done it before ? Any pointers appreciate it
Click to expand...
Eggshell is about 40% by weight calcium. So to make a 4% calcium solution, weigh out 100 g of dry clean eggshell and add 1.00 liter of the usual 5% vinegar solution, and let stand for a few days. The vinegar is your limiting reagent. It is 0.83 molar, assuming you’re using a reputable brand listed at 5%.

This will give you a calcium concentration of
0.41 molar (2 acetic:1Ca). This computes to one point six per cent (w/v) calcium.
 
cannabineer

cannabineer

Ursus marijanus
cannabineer said:
Eggshell is about 40% by weight calcium. So to make a 4% calcium solution, weigh out 100 g of dry clean eggshell and add 1.00 liter of the usual 5% vinegar solution, and let stand for a few days. The vinegar is your limiting reagent. It is 0.83 molar, assuming you’re using a reputable brand listed at 5%.

This will give you a calcium concentration of
0.41 molar (2 acetic:1Ca). This computes to one point six per cent (w/v) calcium.
Click to expand...
I was thinking a 4% solution would be convenient but realized halfway through that the vinegar is too dilute for that. I hope it’s clear.
 
Bignutes

Bignutes

Well-Known Member
Use your ppm meter, take ppm of vinegar and record this number. Then put egg shells in vinegar and let it work away. Then filter the remaining crud out with coffee filter and take the ppm of final solution. Subtract the vinegar ppm from the final ppm and you have your calcium ppm. For me it doesn't matter what the ppm, i ignore the ppm of vinegar its only about 15% of the last solution i made, I add the egg/ca solution to water till it hits 200 ppm above the starting water, then I add Epsom till it hits 50 ppm above that. You could bump up a little. This way its completely dialed in. I love it because it also acts as my ph down, super cheap and I get to eat the egg!
 
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Bignutes

Bignutes

Well-Known Member
Tonycannavis said:
Yes and ph i’m still trying to figure out the Ppm But I know my water is on the green on 15
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Your water is awesome! With a starting ppm of 15 and you want 200 ppm of calcium your target is 215 ppm, 50 ppm of Epsom then puts the final at 265 ppm. I switched to snowfall and runoff and my starting ppm is about 20-30.
 
cannabineer

cannabineer

Ursus marijanus
Bignutes said:
Use your ppm meter, take ppm of vinegar and record this number. Then put egg shells in vinegar and let it work away. Then filter the remaining crud out with coffee filter and take the ppm of final solution. Subtract the vinegar ppm from the final ppm and you have your calcium ppm. For me it doesn't matter what the ppm is because I add the egg/ca solution to water till it hits 200 ppm above the starting water, then I add Epsom till it hits 50 ppm above that. This way its completely dialed in. I love it because it also acts as my ph down, super cheap and I get to eat the egg!
Click to expand...
Won’t work. TDS meters work on ions, and as a weak acid, acetic acid is mostly undissociated and won’t register.

If trying to use TDS to figure the calcium acetate concentration, correct for the fact that there are three ions for every Ca ion.
 
myke

myke

Well-Known Member
cannabineer said:
Won’t work. TDS meters work on ions, and as a weak acid, acetic acid is mostly undissociated and won’t register.

If trying to use TDS to figure the calcium acetate concentration, correct for the fact that there are three ions for every Ca ion.
Click to expand...
Wow,where were you when i made a thread about home made calmag.Awesome stuff!
 
myke

myke

Well-Known Member
Mine went mouldy,I think I went 4 parts V to 1 part eggshell by volume.Ive since rid my garden of calmag and just use epsom and my tap which is hard at 179ppm of Ca mostly.
 
Bignutes

Bignutes

Well-Known Member
cannabineer said:
Won’t work. TDS meters work on ions, and as a weak acid, acetic acid is mostly undissociated and won’t register.

If trying to use TDS to figure the calcium acetate concentration, correct for the fact that there are three ions for every Ca ion.
Click to expand...
So that would mean dividing the ppm by 4 to get calcium?
 
cannabineer

cannabineer

Ursus marijanus
Bignutes said:
So that would mean dividing the ppm by 4 to get calcium?
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I’m not sure. The algorithm is tuned for a mix of mono-and divalent ions. I would approximate bu dividing by 3. Then there is a correction factor for the molecular weight of your ion.
I don’t know how to do that bit. My area is organic synthesis ... different skill set,
 
curious2garden

curious2garden

Well-Known Mod
Staff member
cannabineer said:
I’m not sure. The algorithm is tuned for a mix of mono-and divalent ions. I would approximate bu dividing by 3. Then there is a correction factor for the molecular weight of your ion.
I don’t know how to do that bit. My area is organic synthesis ... different skill set,
Click to expand...
Hit you in the p-chem eh? LOL

Can't you just use a pool Ca hardness meter by Hanna? Or pool Ca test strips or reagent?
 
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