# Epsom Salt usage



## snutter (Dec 18, 2009)

Hey all,

I am just wondering, for those of you out there that use epsom salt (magnesium sulfate) during flower, how much do you use per gallon?

Thanks.


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## Lil Czr (Dec 18, 2009)

I've never measured it, but I just put in a couple pinches. Not very much at all really.


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## snutter (Dec 18, 2009)

Lil Czr said:


> I've never measured it, but I just put in a couple pinches. Not very much at all really.


How much water is in your reservoir?


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## dura72 (Dec 18, 2009)

1 teaspoon per pint. level teaspoon. on day 10 and day 35 of flower. thats what i was told and thats what i follow.works for me buddy.


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## fatman7574 (Dec 18, 2009)

If there is no magnesium sulfate at all in your nutrient formula then add 1 ounces (by weight) ie 28 grams, per every 5 gallons of mixed nutrient water. That would be the equivalent to using a GH formula of Florabloom as Part B of a two Part formula. There is no magnesium Sulfate in their Part A Flora series. That will provide 150 ppm of magnesium.


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## snutter (Dec 18, 2009)

fatman7574 said:


> If there is no magnesium sulfate at all in your nutrient formula then add 1 ounces (by weight) ie 28 grams, per every 5 gallons of mixed nutrient water. That would be the equivalent to using a GH formula of Florabloom as Part B of a two Part formula. There is no magnesium Sulfate in their Part A Flora series. That will provide 150 ppm of magnesium.


Thank you fatman!!! That was exactly the kind of response I was hoping for. It's all in the details people... 

-S


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## snutter (Dec 20, 2009)

fatman7574 said:


> If there is no magnesium sulfate at all in your nutrient formula then add 1 ounces (by weight) ie 28 grams, per every 5 gallons of mixed nutrient water. That would be the equivalent to using a GH formula of Florabloom as Part B of a two Part formula. There is no magnesium Sulfate in their Part A Flora series. That will provide 150 ppm of magnesium.


so I believe that works out to 10 teaspoons for 10 gallons of water... That seems like an awful lot. I could be wrong. I've only been using a healthy pinch... It seems like I could use more, but I just wasn't sure...


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## fatman7574 (Dec 20, 2009)

In lucas formula , which is two parts Bloom and one Part Micro there are 13.5 ounces of magnesium Sulfate in a x100 concentrate. Lucas is remember two parts Bllom. The bllom contains the magnesium sulfate. 13.5/100 = 0.135 ounces per gallon. There are all kinds of approaches and all kinds of opinions. I have no idea how much 0.135 ounces would be in teaspoons. 3.78 grams per gallon if you have a gram scale. Magnesium is a secondary nutrient not a trace nutrient so quaite a bit is used. As you can see below with the Lucas formula there is quite a lot of magnesium used. By weight there is almost as much magnesium sulfate as there is calcium nitrate.

*Formulation:*

*Luca Formula* 

*ppm*
Nitrogen 167
Phosphorus 333
Potassium 397
Magnesium 100 
Calcium 215
Sulfur 133
Iron 3.33
Manganese 1.67
Boron 1.67
Zinc 1.00
Copper .33
Molybdenum .03

*Ounces
PART A*
Calcium Nitrate 14.2
Iron Chelate .45

*Part B
*MonoPotassium Phosphate 21.0
Magnesium Sulfate 13.5
Manganese Sulfate .090
Boric Acid / Solubor.123
Zinc Sulfate .058
Copper Sulfate .020
Ammonium Molybdate .001

Volume of Stock Solutions 1

Dilution Rate 100


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## snutter (Dec 20, 2009)

I'm sorry that you took the time to type that all out, fatman. I just went out surfed it up and read about it cause I do use the lucas formula (your previous post prompted this, especially after I did the conversion to teaspoons). After reading the back of my nute bottles I figured I needed to do myself some learnin. heheh. Thanks for taking the time to put this info here. I am sure it will be a help to other growers in the future. Definitely a great help to me!!!

-S


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## repvip (Dec 20, 2009)

fatman7574 said:


> If there is no magnesium sulfate at all in your nutrient formula then add 1 ounces (by weight) ie 28 grams, per every 5 gallons of mixed nutrient water. That would be the equivalent to using a GH formula of Florabloom as Part B of a two Part formula. There is no magnesium Sulfate in their Part A Flora series. That will provide 150 ppm of magnesium.


 
Epsom salt is magnesium sulfate heptahydrate, so don't forget about the majority of water mass. It may seem like a lot, but it's ~50% water weight, and only ~9% Mg.


MgSO4 = 120.415g/mol
MgSO4*7H2O=246.47g/mol
Mg=24.305g/mol

Using the heptahydrate weight:
28g MgSO4 * 1mol MgSO4/246.47g * 1mol Mg/1mol MgSO4 * 24.305g Mg/mol = 2.761g Mg

I hate ppm conversion, so I approximate using 1 ppm ~= 1mg/Liter
2,761mg Mg/19.2Liter (5 gallon) ~= 143 ppm 

Looks good!!

http://agr.wa.gov/PestFert/Fertilizers/FertDB/Product1.aspx
This website has some interesting fertilizer data, if you decide to make your own... alphabetical listed by manufacturer and sometimes product.

any idea if molasses can be diluted down + epsom salt to make a Sweet or Floranectar type bloom product, for use in hydroponic? Great for dirt, but I'm wondering if a homemade brew would ferment!? ick.


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## fatman7574 (Dec 20, 2009)

Actually (5 gallons/0.2642) = 18.93 liters, so (2761/18.93)= 145.85 ppm or 146 ppm with trucation


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## repvip (Dec 20, 2009)

fatman7574 said:


> Actually (5 gallons/0.2642) = 18.93 liters, so (2761/18.93)= 145.85 ppm or 146 ppm with trucation


oh dang you caught me approximating! 
I've never had a good conversion factor for gal->liter

I was using 960mL/quart so yeah that error added up quick with 5 gallons

Made some homemade Sweet today. Just until I get the real thing.


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## fatman7574 (Dec 20, 2009)

As long as there are areas in your system where there are anoxic conditions the supplemet should be fine. If there are any anoxic spots with anerobic bacteria then expect a bacterial blossom, therefore grey water, possibly smelly. This is usually most commom with systems like DWC and small tube aeros where root health is often questionable and where there are areas where the roots are in low DO water or dead roots and such have accumalated.


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## repvip (Dec 20, 2009)

fatman7574 said:


> As long as there are areas in your system where there are anoxic conditions the supplemet should be fine. If there are any anoxic spots with anerobic bacteria then expect a bacterial blossom, therefore grey water, possibly smelly. This is usually most commom with systems like DWC and small tube aeros where root health is often questionable and where there are areas where the roots are in low DO water or dead roots and such have accumalated.


Thanks for the epsom salt answer that was perfect timing for me. I didn't think to use that much! The math is fun, though.

I evaporated 5mL of Botanicare Sweet and was left with 1.1g residue, which I'm guessing is mostly sugars and mag sulfate. I diluted 20mL molasses +150g epsom salt in 4L, and hope it's a decent match for sweet for a few days. I'm evaporating 5mL of my solution now to see if it's close


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## snutter (Dec 20, 2009)

repvip said:


> Thanks for the epsom salt answer that was perfect timing for me. I didn't think to use that much! The math is fun, though.
> 
> I evaporated 5mL of Botanicare Sweet and was left with 1.1g residue, which I'm guessing is mostly sugars and mag sulfate. I diluted 20mL molasses +150g epsom salt in 4L, and hope it's a decent match for sweet for a few days. I'm evaporating 5mL of my solution now to see if it's close


it all sounds good except the molasses portion.. I don't think molasses does well in hydroponic systems...


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## Silky Shagsalot (Dec 20, 2009)

one teaspoon per gallon.


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## repvip (Dec 20, 2009)

snutter said:


> it all sounds good except the molasses portion.. I don't think molasses does well in hydroponic systems...


Right.. I was wondering about that. Sweet is made from cane sugar.. some other bloom products for hydro are derived from molasses.. so I think it can work. I was more worried about the solution fermenting.

The stock solution is diluted just like Sweet... 10mL per gallon of rez.. it ends up being really dilute molasses and epsoms.


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## llLOU (Dec 20, 2009)

snutter said:


> Hey all,
> 
> I am just wondering, for those of you out there that use epsom salt (magnesium sulfate) during flower, how much do you use per gallon?
> 
> Thanks.


GROWING IN SOIL, I USE 1 tsp. PER GALLON.


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## fatman7574 (Dec 20, 2009)

llLOU said:


> GROWING IN SOIL, I USE 1 tsp. PER GALLON.


100 to 150 ppm.


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## fatman7574 (Dec 20, 2009)

repvip said:


> Right.. I was wondering about that. Sweet is made from cane sugar.. some other bloom products for hydro are derived from molasses.. so I think it can work. I was more worried about the solution fermenting.
> 
> The stock solution is diluted just like Sweet... 10mL per gallon of rez.. it ends up being really dilute molasses and epsoms.


 
The "fermentation" would need yeast (eukaryotes), the bacterial blossom is merely a rapid bacterial growth of the more common bacteria (prokaryotic). They prefer a low pH nitrogen-limiting environment. They are nore common to soil grows whereby there is a lot of petat moss etc. 

The nutrient manfacturers are now pushing carbohydrates rather than the sugar. Same results without the bacterial blossom caused by the sugars. With sugar the exponential growth phase of the bacteria is almost vertical and nearly immediattely while with carbohydrates there is the typical lag phase in growth then the bacterial phase on a growth curve is at about a 45 degree angle. 

The same end results effect is experienced by the plants but over a period of a couple days versus over night.

Sorta like eatting oatmeal verus Captain Crunch. Captain Crunch gives an immediate rush from the sugar and highly processed grain while the merely lighly rolled oats have a more moderated long term nutritional output (staying power).


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## tincdink (Jul 17, 2018)

fatman7574 said:


> If there is no magnesium sulfate at all in your nutrient formula then add 1 ounces (by weight) ie 28 grams, per every 5 gallons of mixed nutrient water. That would be the equivalent to using a GH formula of Florabloom as Part B of a two Part formula. There is no magnesium Sulfate in their Part A Flora series. That will provide 150 ppm of magnesium.


Further proof, the fat man rocks.


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## rkymtnman (Jul 17, 2018)

tincdink said:


> Further proof, the fat man rocks.


i've read alot of what fatman posted and it's good stuff. why was he banned from just about every growing site known to man?? any idea?


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## tincdink (Jul 17, 2018)

rkymtnman said:


> i've read alot of what fatman posted and it's good stuff. why was he banned from just about every growing site known to man?? any idea?


This is the first time I've read a post from him. I was just impressed with what he had to say. Pity he's banned. Nice impressionist CO flag icon btw.


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## dubekoms (Jul 18, 2018)

rkymtnman said:


> i've read alot of what fatman posted and it's good stuff. why was he banned from just about every growing site known to man?? any idea?


I think he ended up being a dick to everyone haha guy was smart though


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## Michael Huntherz (Jul 19, 2018)

snutter said:


> Hey all,
> 
> I am just wondering, for those of you out there that use epsom salt (magnesium sulfate) during flower, how much do you use per gallon?
> 
> Thanks.


I shoot for 50ppm per gallon on the tds meter. What are you using it for?
I use it to get 7ppm of elemental sulfur per gallon, the Mg is a non-issue for me.

I suggest you take about a pound of MgSO4 (500g by weight is a good start) and dissolve it in a gallon of water to make a stock solution, decide what your target MgSO4 ppm is and why, then take some measurements and go from there. It depends what you have going on already. I use MgSO4 from week 2 to week 7, only for the sulfur, because otherwise I don’t have much S in my solution at all. Media, water source and fertilizers you are already using are important factors in this decision.
Do you have a TDS meter? What country did you buy it in? (Seriously) Are you in soil? What are your water source parameters? Fertigation plan? It all matters.


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## rkymtnman (Jul 20, 2018)

Michael Huntherz said:


> I shoot for 50ppm per gallon on the tds meter. What are you using it for?
> I use it to get 7ppm of elemental sulfur per gallon, the Mg is a non-issue for me.
> 
> I suggest you take about a pound of MgSO4 (500g by weight is a good start) and dissolve it in a gallon of water to make a stock solution, decide what your target MgSO4 ppm is and why, then take some measurements and go from there. It depends what you have going on already. I use MgSO4 from week 2 to week 7, only for the sulfur, because otherwise I don’t have much S in my solution at all. Media, water source and fertilizers you are already using are important factors in this decision.
> Do you have a TDS meter? What country did you buy it in? (Seriously) Are you in soil? What are your water source parameters? Fertigation plan? It all matters.


this was a 2009 thread until it was recently revived from the dead. FYI.


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## Michael Huntherz (Jul 20, 2018)

Lol, thanks, @rkymtnman, I constantly get clowned by that.

Necroposting is for winners.


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## rkymtnman (Jul 20, 2018)

Michael Huntherz said:


> Necroposting


love it! i might have to steal that one from you. lol.


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