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Discussion Starter · #3 ·
I suppose we could even go with 3:2:1 ratios depending on how much hardness was desired. This EI isn't rocket science and can be tweaked for specific tanks as needed.

I'm using Plaster of Paris and Epsom salt along with potassium sulfate.
 

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Surely your learning curve isn't restricted to just two subscribers' inputs? The good part of Estimative Index is that it not only allows for estimations, but has plenty of slack for gaining hands-on experience with, and tailoring things to, your own tank and its conditions...

edit - and yes, I know plantbrain is Tom...
 

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their input carries a ton of weight. i would agree with that

HOWEVER tom will likely tell you what his recipe is and that there are many variations which will all work for one tank or another. i believe his is 3 3 1.. u can find it on the barr report..

however different planted environments will accept or sometimes require other amounts which can be adjusted by either ratio OR but just adding more of the whole system.

EI is designed to create non limiting. does it always work.. NOPE. not for my 29gallon. i've had to adjust it to suit my plants needs. Im sure you are aware of the need to adjust. or maybe you aren't EI may fit you perfectly. Its a base line.

That being said. i'd prefer 3 1 1 just because my tank "appears" at this point to need more potassium. but i also need to supply calcium and magnesium in equal amounts since my tap water doesn't seem to provide much of each
 

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Their inputs carry a lot of weight compared to my WAGs. What's your numerical input on this?
With only a few notable exceptions, Lake Tanganyika being the primary, most natural bodies carry about a three-to-one ratio of calcium to magnesium. Potassium is a macro, but not to the extent of calcium in concentration, so it's relegated to the same level as the magnesium.

That gives you a 3:1:1 as a starting point.

But Tom himself will tell you that specific ratios don't necessarily fall within the specific scope of "estimating" other than as a starting point. Mineral and nutrient uptakes aren't affected by the Ca:Mg ratios unless the ratios are extremely skewed, and their total content is more important to the fauna than the flora...
 

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Discussion Starter · #11 ·
aquariumfertilizer.com - Barrs GH Booster is composed of 1 part magnesium sulfate, 3 parts potassium sulfate and 3 parts calcium sulfate.
barrreport.com Originally Posted by Tug - 3 parts KSO4(I think they mean K2SO4), 3 parts CaSO4 AND 1 part MgSO4. I think Tom recommends adding enough to raise the dKH by one degree.
barrreport.com Originally Posted by Tom Barr - GH booster is 2:1:1
K2SO4: CaSO4 : MgSO4

So 1/2 of GH booster is K2SO4 anyway.
barrreport.com Originally Posted by Left C - Barr's GH Booster: http://aquariumfertilizer.com/index....ditU=2&Regit=7
This is Tom Barr's Poor Man's GH Builder/Booster. Barr's GH Booster contains: Potassium Sulfate, Calcium Sulfate, Magnesium Sulfate.
Seachem Equilibrium:
Potassium (K) 19.5%
Calcium (Ca) 8.06%
Magnesium (Mg) 2.41%
So GH booster formulas by volume dry mix...
No unchelated Fe or Mn as my crypts supply all the rust colors desired.

Seachem = 3:1:1
PMDD ver = 3:3:1 ?
Tom's EI ver = 2:1:1 ?

Is this correct?

Edit: thanx jaafaman for the input. Looks like there are some variations to the formulas, but they would all work depending on the tank plants, light & CO2 levels.
 

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So GH booster formulas by volume dry mix...
No unchelated Fe or Mn as my crypts supply all the rust colors desired.

Seachem = 3:1:1
PMDD ver = 3:3:1 ?
Tom's EI ver = 2:1:1 ?

Is this correct?

Edit: thanx jaafaman for the input. Looks like there are some variations to the formulas, but they would all work depending on the tank plants, light & CO2 levels.
No. I've asked barr before. The guy who makes barr booster makes it 3:3:1 Ca:K:Mg by volume.

Seachem's is the same. No idea about pmdd never heard of a gh booster fo pmdd.
 

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Discussion Starter · #13 ·

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Calcium sulfate = food grade Gypsum = CaSO4*2H20 = 172.16 grams/mole (Ca = 23% by wt, SO4 = 55% by wt)

Potassium sulfate = fertilizer = K2SO4 = 174.25 grams/mole (K = 45% by wt, SO4 = 55% by wt)

Magnesium sulfate = MgSO4*7H2O = 150.47 grams/mole (Mg = 16% by wt, SO4 = 64% by wt)

To use round numbers (making the math simple) and the simplistic assumption that these minerals are fairly equal in volume as well, to mix this at 3:3:1 would give a compound that's 10% Ca, 19% K and 2% Mg with about half the weight as sulfate. While there are waters that run 5:1 in Ca:Mg ratios easily enough, to run twice the Ca weight as K doesn't seem quite right - as well as holding a lot of sulfate.

Potassium chloride = salt substitute = KCl = 74.55 grams/mole (K = 52% by wt, Cl = 48% by wt) at about half the weight by volume of the other two in the 3:3:1 mix would give 13% Ca, 13% K and 3% Mg by weight, and only 32% would be SO4 while Cl runs 13%.

Maybe it's just me, but I see this second mix as being a lot closer to what you'd find "out in the world"...


Saw the corrected posting back to Tom's reply after I posted this. The 3:1:1 mix of sulfates is much closer to "natural" ratios.

But personally, I'd still use the KCl to reduce the sulfates a bit and add some chloride...
 

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Discussion Starter · #18 ·
... or CaCl2 to avoid the slow cloudy gypsum dissolution rates.

However since Ca++ is more electropositive than Mg++, mixing them together might result in CaSO4 precipitate anyway.

Also since I'm adding plenty of K in the form of KNO3 & KH2PO4, we don't need gobs of K in the GH booster.

Here's a handy molar weight % calculator.
 

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Sediments usually form after the point of supersaturation, which you won't reach at these concentrations, or in the presence of a precipitating agent, which isn't here. The ions would just remain dissociated in solution...
 
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