2-part DIY (based on jimmy54's theory)

[Tmmste]

Dear All,

I have been working on my version of 2-part for a while. It is based on jimmy54's theory (maybe some can remember jimmy54, he is no longer active). I used his information and altered small bits and pieces. I made it so Na:CI ratio and SO4:CI ratio is similar to natural seawater, combining sodiumcarbonate and sodiumbicarbonate, and for trace elements. For now only strontium/potassium/iodine.
The amount of magnesiumchloride hexahydrate and magnesiumsulphate heptahydrate change if the amount of calciumchloride anhydrate changes. The salinity will stay the same (and the amount of water to remove too).

Magnesium sulphate is dosed seperately from the 2 stock solutions.

Please let me know what you think.

 

[Randy Holmes-Farley]

I'm having a little trouble with the non-english words in the table to know what exactly they are, but a couple of general questions...

One of the basic questions to answer with a two part, for which there is no perfect answer, is how much magnesium to incorporate. How did you decide?

Any special reason to use mostly bicarbonate (aside from the theoretical pH neutrality)? It will necessarily be more dilute, and most folks will benefit from a higher pH boost. I've published DIY recipes using bicarbonate and carbonate, and nearly everyone chooses to use the carbonate recipe.

I definitely agree that potassium is important, but if the recipe is to be potassium neutral, folks would need to know that their calcium chloride does not have substantial potassium in it. Some do, and if folks used that, they may overdose on potassium. Just something to note in using this recipe. In my original DIY recipe, the potassium came from the calcium chloride.

 

[Tmmste]

I'm having a little trouble with the non-english words in the table to know what exactly they are, but a couple of general questions...

One of the basic questions to answer with a two part, for which there is no perfect answer, is how much magnesium to incorporate. How did you decide?

Any special reason to use mostly bicarbonate (aside from the theoretical pH neutrality)? It will necessarily be more dilute, and most folks will benefit from a higher pH boost. I've published DIY recipes using bicarbonate and carbonate, and nearly everyone chooses to use the carbonate recipe.

I definitely agree that potassium is important, but if the recipe is to be potassium neutral, folks would need to know that their calcium chloride does not have substantial potassium in it. Some do, and if folks used that, they may overdose on potassium. Just something to note in using this recipe. In my original DIY recipe, the potassium came from the calcium chloride.

Dear Randy,

I based this on Jimmy's theory; that Mg also uses kH (which explains the drop in kH with kalkwasser despite this being balanced, I believe you said something about that somewhere in your triton test results regarding calcium).
http://www.reefcentral.com/forums/showthread.php?t=2399233&page=2
post #34

For 5,91 sulfate (removed by 2,187L water), I need 15,16gr MgSO47H2O, which contains 1,49gr magnesium, I need 2,95 gr magnesium.. so the difference is added with MgCI26H2O: 12,18 gr.

The calculation for Mg is this: =SOM(((2,8-(("ca depletion per 2,8 kH"/20,039)*2,8))/2,8)*12,1525)/0,119661
So I calculate how much kH is "used" if Ca is for example 18, and the rest is then (18/20*2,8) =around 2,515 kH.. the rest.. 0,285 kH is then used by Mg. 0,285 / 2,8 * 12,15 = 1,237 which can be found in /0,1196 = around 10,33 gr magnesium chloride hexahydrate

I indeed use a bit of sodiumcarbonate to compensate for the pH dip, apart from that I will use and algea turf scrubber as the only source of filtration and think this will keep the pH right where I want it to be. if not, changing the ratio is possible ofcourse. I have no other reason for using mostly bicarbonate.
I intentionally chose anhydrous calcium for its purity, a local supplier has one with hardly any potassium in it. If it would contain the same amount of potassium as an impurity as the source you use, it would almost double indeed (I first used your ratio for deciding how much potassium I would need; 3,6% ppm of Calcium.. although I calculated it now as a fixed % of kH as the amount of Ca difference depending on Mg usage)

In English:

 

[Tmmste]

 

[Randy Holmes-Farley]

There are two reasons to add magnesium to a two part. One issue is consumption, and the other is that the salinity rises, and when you drop the salinity back to normal, you drop everything, including magnesium (just like the need for potassium, which is not primarily consumed, only needed due to salinity changes). I can't really tell if you are accounting for that or not.

In my DIY recipe, I discuss this issue:

An Improved Do-it-Yourself Two-Part Calcium and Alkalinity Supplement System by Randy Holmes-Farley - Reefkeeping.com
http://reefkeeping.com/issues/2006-02/rhf/index.php

from it:

Residual Ions from the Calcium and Alkalinity Parts

Adding 1 gallon of each of these additives will result in a residue of ions remaining after calcification. These are mostly sodium and chloride, and the amounts of those two added are equal in numbers (i.e., moles), but slightly different in weight-based concentrations such as ppm because they do not weigh the same.

After adding 594 grams of baking soda (1 gallon of Recipe #1), we will have added 163 grams of sodium. In natural seawater, magnesium is present at about 12.0% of the sodium concentration (by weight). In order to match the magnesium additions to the sodium additions to leave them in a natural ratio, we need to add 12% of 163 grams, or 19.5 grams, of magnesium for every gallon of the two-part additive that we add.

Additionally, we may want to account for magnesium that is actually incorporated into the coral skeletons. For this calculation, I have assumed that the amount of magnesium incorporated is about 6.5% of the calcium level (by weight), or about 2.5% of the skeleton by weight. In the course of adding this gallon of both parts of the two part supplement, we added 141 grams of calcium, so we need to add 0.065 x 141 = 9 grams of magnesium to account for this deposition.

The magnesium parts of the recipe are designed to add enough magnesium so that it is not depleted by either of the two means described above. Because the magnesium supplement (either version) is 47,000 mg/L in magnesium, we need to add (9 +19.5) grams/47 g/L = 610 ml of the magnesium solution for each gallon of the other parts of Recipe #1.

 

[Tmmste]

There are two reasons to add magnesium to a two part. One issue is consumption, and the other is that the salinity rises, and when you drop the salinity back to normal, you drop everything, including magnesium (just like the need for potassium, which is not primarily consumed, only needed due to salinity changes). I can't really tell if you are accounting for that or not.

In my DIY recipe, I discuss this issue:

An Improved Do-it-Yourself Two-Part Calcium and Alkalinity Supplement System by Randy Holmes-Farley - Reefkeeping.com
http://reefkeeping.com/issues/2006-02/rhf/index.php

from it:

Residual Ions from the Calcium and Alkalinity Parts

Adding 1 gallon of each of these additives will result in a residue of ions remaining after calcification. These are mostly sodium and chloride, and the amounts of those two added are equal in numbers (i.e., moles), but slightly different in weight-based concentrations such as ppm because they do not weigh the same.

After adding 594 grams of baking soda (1 gallon of Recipe #1), we will have added 163 grams of sodium. In natural seawater, magnesium is present at about 12.0% of the sodium concentration (by weight). In order to match the magnesium additions to the sodium additions to leave them in a natural ratio, we need to add 12% of 163 grams, or 19.5 grams, of magnesium for every gallon of the two-part additive that we add.

Additionally, we may want to account for magnesium that is actually incorporated into the coral skeletons. For this calculation, I have assumed that the amount of magnesium incorporated is about 6.5% of the calcium level (by weight), or about 2.5% of the skeleton by weight. In the course of adding this gallon of both parts of the two part supplement, we added 141 grams of calcium, so we need to add 0.065 x 141 = 9 grams of magnesium to account for this deposition.

The magnesium parts of the recipe are designed to add enough magnesium so that it is not depleted by either of the two means described above. Because the magnesium supplement (either version) is 47,000 mg/L in magnesium, we need to add (9 +19.5) grams/47 g/L = 610 ml of the magnesium solution for each gallon of the other parts of Recipe #1.

Randy, the part in the green calculates just that very accurately (left down corner). Compate that box with calculations to the chloride section which states "correction" this is the correction on the elements which are removed with the water. By doing so, SO4 is maintained at 13,8% of Chloride and Sodium 55,7% of Chloride (like natural seawater) If you compare the pictures with 16 Ca and 20 Ca you will notice salinity is maintained and the ratios between Na/CI/SO4 too. Please let me know if something is unclear, I would be more than happy to clarify.

 

[Randy Holmes-Farley]

Randy, the part in the green calculates just that very accurately (left down corner). Compate that box with calculations to the chloride section which states "correction" this is the correction on the elements which are removed with the water. By doing so, SO4 is maintained at 13,8% of Chloride and Sodium 55,7% of Chloride. If you compare the pictures with 16 Ca and 20 Ca you will notice salinity is maintained and the ratios between Na/CI/SO4 too.

Can you just tell me the ratio of the weight of calcium ion to weight of magnesium ion in the overall recipe?

 

[Tmmste]

Can you just tell me the ratio of the weight of calcium ion to weight of magnesium ion in the overall recipe?

Yes ofcourse, I attached a bit more information to it, to show how it should (in theory) balance kH.

Here you see how I got to the total amounts for Mg & Ca (please note that in this example Ca = 18.. when Ca changes.. the amount of calciumchloride and magnesiumchloride changes too.. the amount of magnesium sulfate stays the same)

 

[Randy Holmes-Farley]

Sorry, I still don't follow the table. I'm not questioning its correctness, I just don't see what I want to pull out of it.

Can you just pull out the amount of calcium in grams and the amount of magnesium in grams for some (any) amount of the total recipe?

It's the ratio of the two that I want to check.

I get about 5 for calcium to magnesium by weight in my recipe.

 

[Tmmste]

Sorry, I still don't follow the table. I'm not questioning its correctness, I just don't see what I want to pull out of it.

Can you just pull out the amount of calcium in grams and the amount of magnesium in grams for some (any) amount of the total recipe?

It's the ratio of the two that I want to check.

I get about 5 for calcium to magnesium by weight in my recipe.

I see. Unfortunately I have no fixed ratio, the stock solutions depend on Ca:kH ratio. I get a 5:1 ratio.. when 18,5 Ca is used per 2,8 kH:

Ca 20 - kH 2,8
Ca: 20,9185 gr
Mg; 2,976 gr
Ratio: 7:1

Ca 19 - kH 2,8
Ca: 19,9185 gr
Mg; 3,5824 gr
Ratio: 5,56:1

Ca 18,5 - kH 2,8:
Ca: 19,4185 gr
Mg: 3,8856
Ratio: 5 : 1

Ca 18 - kH 2,8:
Ca: 18,9185 gr
Mg: 4,1889
Ratio: 4,5 : 1

Ca 16 - kH 2,8:
Ca: 16,9185
Mg: 5,4017
Ratio 3,1 : 1

 

[Randy Holmes-Farley]

Why would the ratio vary?

 

[Randy Holmes-Farley]

Never mind. I understand.

 

[Randy Holmes-Farley]

That looks good, but how would you decide which to use?

 

[Tmmste]

That looks good, but how would you decide which to use?

Thank you. If I am not mistaken, kalkwasser is Ca 20 per 2,8 kH. If kH drops and Ca remains the same then Mg should have dropped too. I have no skimmer (diy ATS) so salinity should remain stable. It does depend on the accuracy of the testkits though.

 

[Randy Holmes-Farley]

Right, picking between the choices in the post above about Ca/dKh ratio is essentially picking between different amounts of magnesium incorporation. You can determine it experimentally, but it would take extended measurements to see that so precisely.

 

[Tmmste]

Right, picking between the choices in the post above about Ca/dKh ratio is essentially picking between different amounts of magnesium incorporation. You can determine it experimentally, but it would take extended measurements to see that so precisely.

Recently I made an attempt (I use kalkwasser), but found out the test results where far from precise. The amount of water remains the same, Na:CI:SO4 ratio and dosage too (kH usage remains the same after all). So I could just swap jerrycans if needed. (or calculate how much "more" magnesium chloride needs to be added if less Ca is used.)

I wonder, Randy, do you see any points of improvement regarding this version of 2-part? Thank you very much for your help thusfar, I really appreciate it!

 

[Tmmste]

Right, picking between the choices in the post above about Ca/dKh ratio is essentially picking between different amounts of magnesium incorporation. You can determine it experimentally, but it would take extended measurements to see that so precisely.

Dear Randy, I wondered if you have any last suggestions to improve this way of doing 2-part. I purchased most chemicals and will start making the stock solutions soon.

 

[Randy Holmes-Farley]

Dear Randy, I wondered if you have any last suggestions to improve this way of doing 2-part. I purchased most chemicals and will start making the stock solutions soon.

I’ve lost track. What ingredients do you have at the moment?

 

[Tmmste]

I’ve lost track. What ingredients do you have at the moment?

Dear Randy, this is what it looks like so far:

Part 1 = kH mix, Part 2 = Ca mix. These are the amounts for 1L stock solution. I already made a 10L solution, however, I wondered if you see something which is does not good. Magnesium sulfate I will add seperately.

 

[Randy Holmes-Farley]

Have you ever done an ICP test on your tank water? If it is already high in some things, such as bromide, then it wouldn't be optimal to add more.