# Discus Mix ???



## wkndracer (Mar 23, 2008)

CaSO4
CaCl2
MgSO4
NaSO4 _Substitute_ CaCO3 (to eliminate Na build up)

This is listed here as Discus Mix. *What are the resulting chemistry changes bases on amounts used/added?* I'm finding this site very difficult to navigate. Every time I try to apply information read in this section I'm left with another question! I'm a welder mechanic not a chemist that said I don't feel I'm stupid (most of the time). But PPS and Edwards hard work putting it all together does not result in information I can use at this point. I've used the search for two hours.

Once the ingredients are mixed, how much Discus Mix (gram weight) added to the aquarium = what GH/KH reading? Somehow I cannot locate the volume information.


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## Philosophos (Mar 1, 2009)

4.1 mg/l MgSO4.7H2O =1 dGH
~31.0 mg/l CaSO4.2H2O =1 dGH
17.86 mg/l CaCO3 = 1dKH 1dGH

That bit is from thekrib because I'm too lazy to re-calculate the first two my self.

CaCl2 is something I'm less familiar with. I believe it comes as CaCL2.2H2O but I'm not sure. I'm guessing it drops the Cl2 to become CaO, but I could be wrong. If I'm not, then it's something like 61mg/L for 1dGH

Here's the numbers for anyone who cares to double check me:

Ca: 40.078g/mol x1 = 40.078g/mol
Cl: 35.453g/mol x2 = 70.906g/mol
H: 1.00794g/mol x2 = 2.01588g/mol
O: 15.9994g/mol x4 = 63.9976g/mol

2Cl+2H+4O = 136.91948g/mol

40.078
---------- = ~0.292712
136.91948

17.8575
--------- = ~61.007064
0.292712

~61mg/L CaCL.2H2O = 1dGH


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## wkndracer (Mar 23, 2008)

*Not a chemist*

mol = Molar mass = exactly where I get lost. But thanks very much for responding.

CaSO4 3 grams
CaCl2 1 gram 
MgSO4 1 gram
NaHCO4 1.5 grams is listed by Edward for the discus mix ratio.

Again what I've searched the forum for is the short answer of X grams of discus mix added to X number of gallons provides XdGH, XdKH. Simple as it seems to everyone else listed as it is above that's how I could digest it.
Tomorrow looks to be a day when the above mentioned combination is simply dumped in a gallon of distilled water and the resulting mix tested. (GH, KH)

Philosophos, thanks again for responding.


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## Philosophos (Mar 1, 2009)

How much water is in your column? Not your tank size, but the approximate amount of water once all the hard/squishy stuff displaces some of the volume. Give me that and I'll give you exact numbers. Keep in mind that if you're using tap, there may already be a fair amount of minerals in there.

-Philosophos


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## wkndracer (Mar 23, 2008)

Philosophos said:


> How much water is in your column? Not your tank size, but the approximate amount of water once all the hard/squishy stuff displaces some of the volume. Give me that and I'll give you exact numbers. Keep in mind that if you're using tap, there may already be a fair amount of minerals in there.
> 
> -Philosophos


Well, that's a longer answer is why I'm trying to understand Edwards PPS system. My tanks are filled with 100% R O and currently the system is yielding 0.01 TDS product. My tap is terrible. Two 75g tanks containing 60g, 64g respectively. 55g with a 10g Refugium containing 51 gallons. 55g soil substrate tank containing roughly 47 gallons and a 150g tank yet to be established currently in the garage as I work out the plumbing.

Piggy back arrangement 55g w/Refugium








Bookend 75's








55g soil substrate tank (less than a month set up)


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## Philosophos (Mar 1, 2009)

PPS/PPS pro is something I have yet to get in to. I'm not even sure what's being used as the limiting factor for growth.

If you want to play with ferts outside of systems people have already created, molar conversion is a huge help. Find an online first year chemistry text; it'll walk you through things.

-Philosophos


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## wkndracer (Mar 23, 2008)

Philosophos said:


> PPS/PPS pro is something I have yet to get in to. I'm not even sure what's being used as the limiting factor for growth.
> 
> If you want to play with ferts outside of systems people have already created, molar conversion is a huge help. Find an online first year chemistry text; it'll walk you through things.
> 
> -Philosophos


*"If you want to play with ferts outside of systems people have already created"* Unable to find parameter changes using Edward's stock solution for simple GH/KH/gallon conversion to use the discus mix to set R O.
Applying a mechanics method of see it / touch it. Mixing a single dose measurement in 5 gallons of water and testing the results. Once I get a figure (GH/KH) that will allow PPS to control Ca, Mg and trace through the dosing schedule. I'll use the discus mix to set the R O and go from there.


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## Philosophos (Mar 1, 2009)

Probably best to go that way anyhow; moisture always gets in to crap and throws weights off some. Purity can be a problem, too.

To be honest, you're probably going to end up with more than enough for the discus just from the ferts. I'm using a different fert method, but the minimum requirements for non-limiting growth still adds enough for soft water fish to thrive. Seems like between the macro and trace, osmotic pressure is satisfied.

-Philosophos


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## wkndracer (Mar 23, 2008)

R O used, product reads 0.01TDS to the holding tank GH, KH both read zero on drop tests. 5 gallon measured mix aerated for 24hrs. has yielded 10dGH, 3.5dKH on the following mixture
CaSO4 3 grams
CaCl2 1 gram
MgSO4 1 gram
*CaSO4* 1.5 grams listed by Edward for the discus mix ratio substituted for the baking soda (*NaHCO4*).


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## ray-the-pilot (May 14, 2008)

*Re: Not a chemist*



wkndracer said:


> mol = Molar mass = exactly where I get lost. But thanks very much for responding.
> 
> CaSO4 3 grams
> CaCl2 1 gram
> ...


I think if you put 
CaSO4 3 grams
CaCl2 1 gram 
MgSO4 1 gram
NaHCO4 1.5 grams
in one gal of water it will be fatal for your discus.

GH will be about 45 and KH will be about 13

I'd try this 
CaSO4 0.3 grams
CaCl2 0.1 gram 
MgSO4 0.1 gram
NaHCO4 0.5 grams

This will give a GH and KH of about 4 which is OK for Discus. This may still not be a good discus mix but at least it will not be instantly fatal.


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## wkndracer (Mar 23, 2008)

*Re: Not a chemist*



ray-the-pilot said:


> I think if you put
> CaSO4 3 grams
> CaCl2 1 gram
> MgSO4 1 gram
> ...


Copied from the post listed immediately prior to yours are the results of a test on _*Edwards Discus Mix listed in the PPS guidelines*_. Solution was again 5 gallons of distilled mixed to Edwards listed ratio substituting CaSO4.

R O used, product reads 0.01TDS to the holding tank. GH, KH both read zero on drop tests. *5 gallon measured mix aerated for 24hrs*. has yielded *10dGH, 3.5dKH *on the following mixture. Results stated based on API drop tests.
CaSO4 3 grams
CaCl2 1 gram
MgSO4 1 gram
*CaSO4* 1.5 grams listed by Edward for the discus mix ratio substituted for the *baking soda (NaHCO4). *

This mix did yeild 50dGH, 17.5dKH if mixed in one gallon of my distilled water. Based on API drop tests.


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## ray-the-pilot (May 14, 2008)

*Re: Not a chemist*



wkndracer said:


> R O used, product reads 0.01TDS to the holding tank. GH, KH both read zero on drop tests. *5 gallon measured mix aerated for 24hrs*. has yielded *10dGH, 3.5dKH *on the following mixture. Results stated based on API drop tests.
> CaSO4 3 grams
> CaCl2 1 gram
> MgSO4 1 gram
> ...


Did you use CaSO4 as a NaHCO3 substitute or CaCO3?

You should have almost 0 deg. KH using extra CaSO4.

Using:

CaSO4 3 grams
CaCl2 1 gram
MgSO4 1 gram
*CaCo3* 1.5 grams 
in 5 gal of water should give a GH of about 13.5 and a KH of about 4.4, which is pretty close to what you got.


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## wkndracer (Mar 23, 2008)

Used CaSO3 as a NaHCO3 substitute. Typo crept in with the time pressure of life. Should have skipped the follow up until another day.

If the guideline is clearly explained then it's a matter of proper measurement and correct testing. 
Reference material for the PPS method has a couple of gaps.


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