# Calcium:Magnesium ratio 4:1 or 1:4



## grshs_vny

Guys from the beginning of my tank i am having Ca:Mg problem, i have a very soft water supply and its gh is around 3 so i have to adjust every time i change water.Am really frustrated seeing my plants leaves curling .When add ca ,mg deficiency shows up and vice versa ,i tried 4:1(Ca:Mg) but it is not working and here i read that exact opposite works for aquatic plant but i really dont know. anyone here ever tried this ratio? OR the whole idea of ratio is senseless?because few guys say as long as you have required amount of nutrient no ratio matters.if that s true then there should not be a problem with me cos i dose 10ppm ofMg,40ppm of Ca,20ppm of K, 1ppm of P.Please guy help me am really looking for advise.
My tank is 55g ,am really sure i have good circulation ,co2 concentration.am using 4 wpg t5 lights,ada amazonia II and using EI :frusty::frusty::frusty::frusty::frusty::frusty::frusty::frusty::frusty:


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## darkoon

3dGH should be good enough, i suspect you either have insufficient co2 or have other micro deficiencies, such as boron or iron.


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## Seattle_Aquarist

Hi grshs vny,

Per Seachem (in our own APC Sponsor sub-forum) this is the information on Seachem Equilibrium:


> The ratio is about 3.3:1, Ca:Mg.


.

Equal amounts of CaCl (Air-Dri) and MgSO4 (Epsom Salt) will give you approximately the above ratio.


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## Izzy

Seattle_Aquarist said:


> Hi grshs vny,
> 
> Per Seachem (in our own APC Sponsor sub-forum) this is the information on Seachem Equilibrium:
> 
> 
> 
> The ratio is about 3.3:1, Ca:Mg.[/QUOTE.
> 
> Equal amounts of CaCl (Air-Dri) and MgSO4 (Epsom Salt) will give you approximately the above ratio.
> 
> 
> 
> Is Air-Dri pure CaCl? I'm getting ready to place a ferts order and the 2.2 lbs for $6 at the Home Depot will cut down on shipping and product expenses.
> 
> Thanks, sorry, this is not meant to hijack the thread.
Click to expand...


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## Seattle_Aquarist

Hi Izzy,

Dri-Z-Air is over 90% pure Calcium Chloride (CaCl); per the MSDS here are the ingredients:


> 3. COMPOSITION/INFORMATION ON INGREDIENTS
> 
> Component Percentage CAS Number
> Calcium chloride > 90.0% - < 92.0%
> Potassium chloride > 2.0% - < 3.0%
> Water > 4.0% - < 6.0%
> Sodium chloride > 1.0% - < 2.0%
> Calcium bromide (CaBr2) <1%


I like CaCl because it dissolves clear and does not turn the water "milky". The only hassle is the fact that it creates an exothermic reaction with water (generates heat) and so I dissolve it outside the aquarium before adding it.


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## grshs_vny

O.k the ratio is 3.3:1 so the ratio thing is necessary .Am i right? I have optimum concentration of CO2 in my water so i have to rule out this one,you people say 3dgh is good enough so i think i might be overdosing any one of the two.
here is the complete details of my tank and the dosing regime
Tank capacity 55G ,it is 60cm in vertical height.I use 39*4 t5 and 34*2 pl ,amzoniaII,pressurized CO2, eheim pro3,trace mix,12%Fe edta and macros.am following EI.I use JBL 5 in 1 test strips. my water supply has 0 NO3,0 NO2,3-4 dgh, 5dkh and 6.4 ph. 
Every sunday i change60% of water
monday i dose 40ppm 0f calcium through CaCl2,10 ppm of Mg through MgSO4,20 ppm of potassium,10 ppm of NO3 and 1 ppm of PO4.
On tuesday i dose micro and iron am well aware it has around 3% boron.
I repeat this cycle till next water change.i dont care about the remaining nutrient in the water column while dosing next time.whenver i test my water between monday and saturday NO3 remains 25ppm and gh remains between14-20dgh.
Plants show good amount of pearling and growing very rapidly.rotala roundifolia , baby tears shows the deficiency alot.From past two days tonina belem is showing white streak patches .i suspect the issue is not because of deficiency but from massive imbalance.So i need to know how and how much to dose.


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## Seattle_Aquarist

Hi grshs_vny,



> O.k the ratio is 3.3:1 so the ratio thing is necessary .Am i right? I have optimum concentration of CO2 in my water so i have to rule out this one,you people say 3dgh is good enough so i think i might be overdosing any one of the two.


Tom Barr spoke here two months ago and one of the things discussed was our very soft Seattle (3.0 dGH) water. He doesn't worry about his dkH but he does try for about 5.0 dgH.

He stated that the formula for GH Booster (which he gave to aquariumfertilizer.com) is basically 1/2 K2SO4; 1/4 Gypsum (CaSO4); and 1/4 Epsom Salts (MGSO4). Please note that his forumla includes Potassium Sulfate.

Let's go back to your original post, your problem is "curling leaves". You stated you have "optimum CO2"....how do you check your CO2 and what PPM?

Currently, when you add ca and mg does the problem go away but then return?


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## grshs_vny

I use ADA dropcheker and my CO2 concentration is 30ppm ,am using a glass diffuser and powerhead to distribute CO2.Thats correct when i add Mg today Ca defiency shows up tomorrow and vice versa.With this problem i added nearly 20ppm of Mg from past four days.now am not following any regime for Mg and Ca am simply adding these things as i notice defeciency.By the way why are asking for CO2 concentration am sure its not CO2 because when there is Mg deficiency leaf becomes pale an veins remains dark green.Now any idea?


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## khanzer22

Please correct me if I'm wrong, you're adding 20ppm of Mg? Seems your dosing too much of this as well as Ca... My tap is only 2-3dGH and I only add a teaspoon of Equilibrium in my 37gal tank after WC, that's it, no more... What other plants you have in your tank btw?

I've read OR someone told me about K > Ca > Mg/N (not sure which one) relationship... If one is greater than the other in that order, plants will stop absorbing the below nutrient (ex. Ca > K)... When you do WC this weekend, do 50% and lower your Mg/Ca dosage to 2-4ppm and 10ppm (respectively) then observe for a week or 2 if there are changes... Just my 2 cents

Keep us posted...


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## darkoon

I personally think you might be dosing too much fert, as khanzer22 pointed out, too much Ca and Mg. The EI target is for end of week not per day dosage. and did you find out how much ca and mg are in your 3-4dGH tap water before you decide how much of ca and mg to dose?
the reason I asked about CO2 is that without sufficient CO2, plants will not be able to utilize other nutrition regards how much is in the water. 
the last thing, with your 4wpg lighting, how long do you leave you lights on?


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## barbarossa4122

I dose about 7ppm Mg and 25ppm Ca /week via Epsom, Cacl2, Equilibrium and Barr's booster.


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## niko

Yes you are right. The whole idea of a ratio is useless.

You can keep the ratio perfect and you will eventually learn that it's pointless.

But give it a try, get an opinion yourself.

--Nikolay


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## grshs_vny

khanzer22 said:


> Please correct me if I'm wrong, you're adding 20ppm of Mg? Seems your dosing too much of this as well as Ca... My tap is only 2-3dGH and I only add a teaspoon of Equilibrium in my 37gal tank after WC, that's it, no more... What other plants you have in your tank btw?
> 
> I've read OR someone told me about K > Ca > Mg/N (not sure which one) relationship... If one is greater than the other in that order, plants will stop absorbing the below nutrient (ex. Ca > K)... When you do WC this weekend, do 50% and lower your Mg/Ca dosage to 2-4ppm and 10ppm (respectively) then observe for a week or 2 if there are changes... Just my 2 cents
> 
> Keep us posted...


No no 20ppm of Mg is the total amount added in four days.The ratio is Ca>K>Mg and there is 3:1 ratio between N and P.
Now back to my tank ,I did 60% water change yesterday and added no nutrients.The water parameters after water change 
NO3--5PPM
NO2--0PPM
GH--7-8dGH
KH--6dKH
Ph--6.8.
and all plants looked o.k. that dose'nt mean problem solved,older leaves and stems are still bent downwards but new growth is straight.And plants are pearling crazily.
Now to ratio part,there is relation between ratio and uptake of nutrients at different ph, i'll talk about this later .At this point i can only say it is better to consider ratio.
I WISH HAPPY CHRISTMAS TO ONE AND ALLartyman:


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## Newt

Why not just dose 50:50 Ca:Mg


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## Seattle_Aquarist

Hi grshs_vny,

I seldom, if ever, have see older leaves that show the effects of deficiencies "correct" themselves after I have corrected the deficiecy. They seem to remain bent, curled, stunted, etc. until they are physically removed. I judge how I am doing by the new growth, not the older growth.


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## grshs_vny

O.k my plants looks a lot better today.you are right older leaves never turns good once they become deficient.Today i did macros for the second time & plants pearling even more crazily especially after upping PO4,it is at 1ppm.Am keeping 3.3:1 ratio for Ca & Mg respectively,nitrates are below 15ppm,K approximately 20ppm ,I added a pinch of boric acid.Because of my previous (before water change)addition of calcium and magnesium at large amounts i noticed potassium deficiency (pinholes)and affected leaves are floating.This means higher amounts of calcium induces potassium deficiency.Now am little bit relieved.eace:


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## Seattle_Aquarist

Hi grshs_vny,

I am glad to hear your plants are doing better. It is amazing how quickly they respond when I start doing things correctly!


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## grshs_vny

I finally found the culprit ,it is indeed the ratio that is already present my water supply.I bought some lab grade test kits and tested my tank water,it had 30 ppm Ca and 33ppm Mg,then tested main water supply it has 30 ppm Ca and 24.3 ppm Mg.after this result i added 78 ppm Ca through CaCl2 and the plants are looking good no more twisting and curling.even at this high Ca concentration no Mg deficiency.But if i run all my lighting then there will be a mild Mg deficiency.At present am running (39*4)watt HO T5.Ratio really matters when it comes to certain nutrients.But after having this kind of concentration tonina is turning brow-black.Is there any way to manage this situation other than RO.


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## darkoon

grshs_vny said:


> I finally found the culprit ,it is indeed the ratio that is already present my water supply.I bought some lab grade test kits and tested my tank water,it had 30 ppm Ca and 33ppm Mg,then tested main water supply it has 30 ppm Ca and 24.3 ppm Mg.after this result i added 78 ppm Ca through CaCl2 and the plants are looking good no more twisting and curling.even at this high Ca concentration no Mg deficiency.But if i run all my lighting then there will be a mild Mg deficiency.At present am running (39*4)watt HO T5.Ratio really matters when it comes to certain nutrients.But after having this kind of concentration tonina is turning brow-black.Is there any way to manage this situation other than RO.


if you have 30ppm of Ca and 24ppm of Mg in your tap water, how can it be only 3dGH?
the only option to lower your GH is to use RO water.


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## Newt

darkoon said:


> if you have 30ppm of Ca and 24ppm of Mg in your tap water, how can it be only 3dGH?
> the only option to lower your GH is to use RO water.


That would be correct:

30 + 24 = 54ppm/17.85 = 3.025 dGH


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## darkoon

Newt said:


> That would be correct:
> 
> 30 + 24 = 54ppm/17.85 = 3.025 dGH


incorrect according to this 
http://www.aquaticplantcentral.com/...hemical-mass-solubility-conversions-test.html

7.144 Ca ppm = 1 dGH = 17.86 ppm GH
4.356 Mg ppm = 1 dGH = 17.86 ppm GH

so you should have 30/7.144 + 24/4.356 = 9.7 dGH


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## bosmahe1

It seems to me that there is more than sufficient amounts of ca and mg already.


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## grshs_vny

Thats correct.Even though i have sufficient concentration Ca and Mg ,it is completely out of ratio this is what causing the problem.Am just increasing calcium up to 60 ppm adding 26 ppm of Ca simply to maintain ratio and it is really helping.


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## MacFan

I did my calculations using Rex Grigg's site:
http://www.rexgrigg.com/waterchem.htm

"0.79 grams of calcium chloride and 0.33 grams of Epsom salts will raise 10 gallons of water about 1° of gH."

I measured by weight and then found volume measurements that were close enough. The ratio was rough 3 parts Calcium Chloride to 1 part Magnesium. I found that adding the same amount of baking soda as I added of calcium chloride was right to get my goal of 4GH/4KH. So for my 150g tank which I measured to be about 100g of water, a 50% water change gets 1Tbsp calcium, 1tsp magnesium, 1Tbsp baking soda.


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## Yo-han

darkoon said:


> incorrect according to this
> http://www.aquaticplantcentral.com/...hemical-mass-solubility-conversions-test.html
> 
> 7.144 Ca ppm = 1 dGH = 17.86 ppm GH
> 4.356 Mg ppm = 1 dGH = 17.86 ppm GH
> 
> so you should have 30/7.144 + 24/4.356 = 9.7 dGH


NEWT is right, 1 GH = 17.86 ppm of Ca2+ and Mg2+ combined.

So if Ca = 30 and Mg = 24, then GH = 54 ppm, thus 54 / 17.86 = 3,024 dGH (we are talking german degrees of hardness here)

Not sure what Edward was meaning with the 7.144 Ca ppm and 4.356 Mg ppm, but the second half of that mini table is what you need.

Besides, otherwise most planted tank owners would have a hardness, way higher than a lake tanganyika biotope

To answer the original post, I think these ratio's are more of a guideline. I too had problems with magnesium defiencies, but I found out that my deficiency was causes by high potassium. High potassium inhibits the uptake of magnesium. So even with high magnesium I still saw a deficiency. Magnesium promotes the uptake of iron, so because of my high potassium levels I was having a iron deficiency as well. High Iron concentrations worked a little and pinholes stopped appearing. After lowering my potassium dosing the magnesium defiency cleared up and the iron deficiency as well. 
I hope you are not still having these problems, but if they return, check your potassium dosing. (this is dosed bij KNO3 and most iron and trace mixes, besides K2S04) Also high sulphur and high calcium inhibit magnesium uptake. Everything is connected and a deficiency is often caused by inhibition of an excess of another element, the so called antagonist. So the ratio comes as a guideline and not a strict rule, but if you go to far off, one element can start inhibiting others.

Regards,
Johan


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## Newt

There's 2 hardness scales from what I remember. Most people use the German hardness scale with the lower case d vs DGH or DKH.


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## ray-the-pilot

grshs_vny said:


> On tuesday i dose micro and iron am well aware it has around 3% boron.


You also said you added a pinch of boric acid to your tank.
You are aware the boron is an ultra trace nutrient. The correct levels are in the parts per billion! Above 1 ppm part per million, boron (in the form of boric acid is toxic to plants causing leaf necrosis and death.

Maybe you shold monitor the amount of boron you are adding?


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## bosmahe1

I don't remember where I got this conversion but, I compared it to the DC water report and what I've measured with AP GH test kit and it seems to match up.

GH Conversion 
(2.5 x Ca ppm) + (4.1 x Mg ppm) = GH ppm 

GH ppm/17.86 = dGH 

DC Water	

(2.5 x 40) + (4.1 x 8.8 ) =
100+36.08=136.08
136.08/17.86=7.62 dGH


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## Coralite

My water is uber soft out of the tap, less than 1 GH and KH. I pay little no attention at mineralizing the water. Plants love it soft and the only deficiencies I ever see are lack of K and lack of N. At the very most I add a dash of equilibrium every now and then.


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## niko

Don't listen to Coralite. He grows only rare plants that love soft water. He doesn't understand how complex planted tank fertilization really is.

You need to find the answer using testing, calculations, and precise dosing. 

If you figured Amano doesn't know exactly how much his Ca:Mg ratio is you are mistaken. Unfortunatelly we don't have much information about that and are left on our own to figure it out.

I suggest you also try to learn about the interactions of trace elements with each other and with N, P, K or Fe.

Keep trying, success is near!

--Nikolay


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## ray-the-pilot

bosmahe1 said:


> I don't remember where I got this conversion but, I compared it to the DC water report and what I've measured with AP GH test kit and it seems to match up.
> 
> GH Conversion
> (2.5 x Ca ppm) + (4.1 x Mg ppm) = GH ppm
> 
> GH ppm/17.86 = dGH
> 
> DC Water
> 
> (2.5 x 40) + (4.1 x 8.8 ) =
> 100+36.08=136.08
> 136.08/17.86=7.62 dGH


You got this from me. I posted it back in 7/28/10. I don't know how to set a link to this post but this GH discussion goes along with what I've said many times before that GH is a bogus number that is basically usless for any aquarium use. Can you set the link for me?


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## ray-the-pilot

Yo-han said:


> NEWT is right, 1 GH = 17.86 ppm of Ca2+ and Mg2+ combined.
> 
> So if Ca = 30 and Mg = 24, then GH = 54 ppm, thus 54 / 17.86 = 3,024 dGH (we are talking german degrees of hardness here)


This is wrong. Edwards formulae were correct.

I've tried at least 3 times to get people to simply stop using any reference to GH. This is because GH is a meaningless number for anything to do with plants.

Here is the way GH is calculated. It assumes that Mg and Ca are equivalent on a MOLAR basis (not a gram or mg basis).
Then it converts the moles of each to grams of CaCO3
So if you have 7.144 ppm of Ca
7.144 /mol mass Ca * mol mass of CaCO3 = 7.144 /40.*100.= 17.86 ppm GH

or for 30 ppm Ca and 24 ppm Mg is

30 * 2.5 = 75
24 * 4.1 = 98 (notice the different conversion factor here)
total = 75 + 98 = 173 ppm total hardness


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## bosmahe1

Ray,

I had that conversion in my notes so I apologize, I don't have the link. I'm must have found it in my searching through the PPS Pro threads where Edward and you were large contributors. I will see if I can find it though.


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## bosmahe1

Ray,

Can you explain why GH is not useful?


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## bosmahe1

ray-the-pilot said:


> You got this from me. I posted it back in 7/28/10. I don't know how to set a link to this post but this GH discussion goes along with what I've said many times before that GH is a bogus number that is basically usless for any aquarium use. Can you set the link for me?


I'm guessing this is where I first saw this conversion, under the heading *GH Testing*:

http://www.aquaticplantcentral.com/...hemical-mass-solubility-conversions-test.html


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## Newt

I find it odd that 2 of my hardness test kits match the way I've been calculating GH. I havent had time to review Baench where he discusses the two hardness scales. But I will.


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## Newt

Copied and pasted from Wikipedia>>>

Hardness can be quantified by instrumental analysis. The total water hardness, including both Ca2+ and Mg2+ ions, is reported in parts per million (ppm) or weight/volume (mg/L) of calcium carbonate (CaCO3) in the water. Although water hardness usually measures only the total concentrations of calcium and magnesium (the two most prevalent divalent metal ions), iron, aluminium, and manganese can also be present at elevated levels in some locations. The presence of iron characteristically confers a brownish (rust-like) colour to the calcification, instead of white (the color of most of the other compounds).

Because it is the precise mixture of minerals dissolved in the water, together with the water's pH and temperature, that determines the behavior of the hardness, a single-number scale does not adequately describe hardness. Descriptions of hardness correspond roughly with ranges of mineral concentrations:[15]

Soft: 0-60 mg/L 
Moderately hard: 61-120 mg/L 
Hard: 121-180 mg/L 
Very hard: >181 mg/L

The level of total hardness in water can be evaluated with commercial testing kits, which measure the concentrations of calcium and magnesium. Several scales are used to describe the hardness of water in different contexts. The hardness is indicated by a calculation where both calcium and magnesium values are reported as mg/L (ppm) (Ca x 2.5) + (Mg x 4.12)= Hardness in mg/L

Parts per million (ppm)
Usually defined as one milligram of calcium carbonate (CaCO3) per liter of water (the definition used below).[16]
Grains per Gallon (gpg)
Defined as 1 grain (64.8 mg) of calcium carbonate per U.S. gallon (3.79 litres), or 17.118 ppm
mmol/L (millimoles per litre)
One millimole of calcium (either Ca2+ or CaCO3) per litre of water corresponds to a hardness of 100.09 ppm or 5.608 dGH, since the molar mass of calcium carbonate is 100.09 g/mol.
Degrees of General Hardness (dGH)
One degree of General Hardness is defined as 10 milligrams of calcium oxide per litre of water, which is the same as one German degree (17.848 ppm).
Various alternative "degrees": 
Clark degrees (°Clark)/English degrees (°e or e)
One degree Clark is defined as one grain (64.8 mg) of calcium carbonate per Imperial gallon (4.55 litres) of water, equivalent to 14.254 ppm.
German degrees (Deutsche Härte, °dH or dH)
One degree German is defined as 10 milligrams of calcium oxide per litre of water. This is equivalent to 17.848 milligrams of calcium carbonate per litre of water, or 17.848 ppm.
French degrees (°F or f) (letter written in lower-case to avoid confusion with degree Fahrenheit - not always adhered to)
One degree French is defined as 10 milligrams of calcium carbonate per litre of water, equivalent to 10 ppm.
American degrees
One degree American is defined as one milligram of calcium carbonate per litre of water, equivalent to 1 ppm.
Although most of the above measures define hardness in terms of concentrations of calcium in water, any combination of calcium and magnesium cations having the same total molarity as a pure calcium solution will yield the same degree of hardness. Consequently, hardness concentrations for naturally occurring waters (which will contain both Ca2+ and Mg2+ ions), are usually expressed as an equivalent concentration of pure calcium in solution. For example, water that contains 1.5 mmol/L of elemental calcium (Ca2+) and 1.0 mmol/L of magnesium (Mg2+) is equivalent in hardness to a 2.5 mmol/L solution of calcium alone (250.2 ppm).


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## wet

bosmahe1 said:


> Ray,
> 
> Can you explain why GH is not useful?


I'm going to try to field this one, and I hope that's alight, boshame1, while operating under the principle that one of our gardeners (maybe ray-the-pilot) will correct me if this is fundamentally wrong:

Since GH measures the sum of Ca and Mg while ignoring minimum thresholds for each, it is a misleading statistic unless used in conjunction with a Ca test kit (more
common) or a Mg kit. Both Ca and Mg are critical for plant growth.

Let's, for a moment, imagine tap water that comes from a reservoir with high amounts of natural limestone: This water will have very high Ca and GH of, let's say, 5 degrees, leading most aquarists only measuring GH to believe their water is fine with only N, P, K and general trace (say Flourish or CSM+B dosing) addition. However, in practice that same tank may have many problems with algae or stunted growth since Mg is lacking. The aquarist only measuring GH would be oblivious to this.

Which brings up an argument for classic EI, which would add GH booster - which is designed to have Ca and Mg sources in good proportion - or Seachem Equilibrium - same - blindly. Such a dosing schedule would meet minimum requirements for both Mg and Ca, and it is no coincidence that EI also recommends never trusting any test kit.

A recommeded method by this gardener is:

A) if using tap: obtain your city's water quality report. In the US this is easy and regulated by agencies and stuff. If you have enough Ca (>20ppm) but not enough Mg, add Epsom salt. If vice versa, add CaCl2 or CaSO4. If both are good (like my tap in Los Angeles, CA) forget about it.

B) if using RO/DI or softwater tap, pick up Equilibrium or GH Booster and dose to recommended values. Then forget about GH because you have more important things (larger micros, like C or N) to worry about.

C) regardless of A or B, keep in mind that Claus (formerly of Tropica, and via the AGA convention) measured that the most consistent value in the wild (Sir Lanka, the Amazon, etc) was GH. I believe this indicates that if you do decide to move GH/Ca/Mg, you do it slowly while keeping an eye on your fauna.

Hoping this helps!


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## bosmahe1

wet said:


> I'm going to try to field this one, and I hope that's alight, boshame1, while operating under the principle that one of our gardeners (maybe ray-the-pilot) will correct me if this is fundamentally wrong:
> 
> Since GH measures the sum of Ca and Mg while ignoring minimum thresholds for each, it is a misleading statistic unless used in conjunction with a Ca test kit (more
> common) or a Mg kit. Both Ca and Mg are critical for plant growth.
> 
> Let's, for a moment, imagine tap water that comes from a reservoir with high amounts of natural limestone: This water will have very high Ca and GH of, let's say, 5 degrees, leading most aquarists only measuring GH to believe their water is fine with only N, P, K and general trace (say Flourish or CSM+B dosing) addition. However, in practice that same tank may have many problems with algae or stunted growth since Mg is lacking. The aquarist only measuring GH would be oblivious to this.
> 
> Which brings up an argument for classic EI, which would add GH booster - which is designed to have Ca and Mg sources in good proportion - or Seachem Equilibrium - same - blindly. Such a dosing schedule would meet minimum requirements for both Mg and Ca, and it is no coincidence that EI also recommends never trusting any test kit.
> 
> A recommeded method by this gardener is:
> 
> A) if using tap: obtain your city's water quality report. In the US this is easy and regulated by agencies and stuff. If you have enough Ca (>20ppm) but not enough Mg, add Epsom salt. If vice versa, add CaCl2 or CaSO4. If both are good (like my tap in Los Angeles, CA) forget about it.
> 
> B) if using RO/DI or softwater tap, pick up Equilibrium or GH Booster and dose to recommended values. Then forget about GH because you have more important things (larger micros, like C or N) to worry about.
> 
> C) regardless of A or B, keep in mind that Claus (formerly of Tropica, and via the AGA convention) measured that the most consistent value in the wild (Sir Lanka, the Amazon, etc) was GH. I believe this indicates that if you do decide to move GH/Ca/Mg, you do it slowly while keeping an eye on your fauna.
> 
> Hoping this helps!


Thanks, that should have been obvious to me. GH doesn't indicate whether you're measuring Ca hardness or Mg hardness or both. Since, it would be unlikely that somebody would have medium hard water that was absent of calcium maybe, just having a magnesium test kit would suffice. I remember reading somewhere that the available type of magnesium may not be ideal for plants either so, adding Mg might still be a good idea. I haven't read if the same applies to calcium.

The Leesburg Virginia water report just indicates that total hardness varies between 130 and 170 ppm. Gee, I'm glad they narrowed it down for us. 

Anyway, Washington DC sources their water from the Potomac river also, and breaks it down as, Calcium ppm is 40 on average and Magnesium ppm is 8.8 on average. The ratio doesn't look to bad either. They further indicate that calcium hardness is 102 ppm on average and total hardness is 137 ppm. These numbers support:

(2.5 x Ca) + (4.1 x Mg) = Total Hardness


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## ray-the-pilot

wet said:


> C) regardless of A or B, keep in mind that Claus (formerly of Tropica, and via the AGA convention) measured that the most consistent value in the wild (Sir Lanka, the Amazon, etc) was GH. I believe this indicates that if you do decide to move GH/Ca/Mg, you do it slowly while keeping an eye on your fauna.
> 
> Hoping this helps!


Firstly, thanks for picking up for me. I couldn't have said it better myself.

I believe that GH is very stable in the wild in the Amazon and Sri Lanka since these are essentially tropical rain forests with continuous supply of soft (rain) water.

My personal experience with my Amazon biotype is this. I have a 52 gal tank. On Saturday, I take out about 5 gal of water and put back 5 gal of RO water. On Sunday, I take out 5 gal of water and put back 2.5 gal of seasoned + Prime city water and 2.5 gal of RO water.

I've tested my water up/down and sideways and know that this ratio keep Ca at 40 PPM (as CaCO3) and Mg at 20 PPM ( as CaCO3).


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## cliffclof

> I think the 1:4 Ca:Mg (Calcium:Magnesium) ratio idea is when people measure the total weight of MgSO4 and CaCl or CaSO4. If that is correct the actual Ca:Mg weight ratio is about 1 : 2.
> 
> I'm just thinking that if I really wanted to hit a ratio of 1:4 Ca:Mg using MgSO4 and CaCl I would have to add a h^ll of a lot of sulfates to get that Mg qty up there. Or have very very soft water.
> 
> I would love to hear some educated comments on this.


?? In my experience a target ratio of 4:1 is good, but I always add extra Mg because my plants seem to use it up faster. The final ratio I hit upon dosing is usually around 2.5 or 3 : 1. My Rotala's love the Mg under bluer light.


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## ray-the-pilot

cliffclof said:


> ?? In my experience a target ratio of 4:1 is good, but I always add extra Mg because my plants seem to use it up faster. The final ratio I hit upon dosing is usually around 2.5 or 3 : 1. My Rotala's love the Mg under bluer light.


Sad as this is you didn't tell us anything! And it is not your fault! 
You need to tell us what form the Ca and Mg are in: Ie are they as Ca+,Mg+ or CaCO3. If you are testing your water you need to specify how the test is reporting the results.
As I've said before, the whole Ca-Mg-GH thing is a mess that needs to be addressed by the amateur plant growing community.


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## cliffclof

I am very well aware of the problems in the hobby when beginners are learning about Total Hardness, Calcium, Magnesium, Alkalinity and all the names associated with them. The major problem is understanding that Total Hardness (GH) can be a part of Alkalinity (KH), or not contribute to alkalinity at all depending upon what type of calcium and magnesium is added to the aquarium. You know this and I know this, just fixing my assumption mistake. Also the fact that most tests represent the Ca and GH differently really causes trouble as you say.

I assumed too much from the previous post where I explained my ratios as Ca:Mg. My assumption was what I should not have done, to think my ratio would be taken as the ratio of Ca:Mg as I had expressed in the quote. And it isn't my ratio obviously, it is just the one that I have tested that a lot of others swear by.

So yes it is Ca:Mg.


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## ray-the-pilot

cliffclof said:


> I am very well aware of the problems in the hobby when beginners are learning about Total Hardness, Calcium, Magnesium, Alkalinity and all the names associated with them. The major problem is understanding that Total Hardness (GH) can be a part of Alkalinity (KH), or not contribute to alkalinity at all depending upon what type of calcium and magnesium is added to the aquarium. You know this and I know this, just fixing my assumption mistake. Also the fact that most tests represent the Ca and GH differently really causes trouble as you say.
> 
> I assumed too much from the previous post where I explained my ratios as Ca:Mg. My assumption was what I should not have done, to think my ratio would be taken as the ratio of Ca:Mg as I had expressed in the quote. And it isn't my ratio obviously, it is just the one that I have tested that a lot of others swear by.
> 
> So yes it is Ca:Mg.


This is almost OK but there is still a problem. My water is 17.0 ppm Ca and 7.1 ppm Mg this is a ratio of 17.0/7.1 = 2.4. I could get this ratio at Ca = 24000, Mg = 10000 and Ca = .24, Mg = .1. These have the right ratio but would not be good plant growing tanks.

You need to report Ca in ppm and Mg in ppm nothing else will do!


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