When Calcium, Alkalinity and Magnesium Demand Does not Balance

[pierpoljam]

I have been struggling with the weirdest issue for the past few months; my calcium and magnesium always seems to go downhill while my alkalinity is on the rise. I'm dosing Kalkwasser at night as a primary source and balanced 2 part + magnesium to complement. I have redundancy in testing with Hanna and Salifert kit as I am skeptical about home made tests. As for nutriments: My Nitrates were also going uphill ( carbon dosing helped ) while I'm dosing phosphate to keep it from bottoming out. My Ph is fairly stable at around 8.1 +/- 0.05

 

[Randy Holmes-Farley]

Which two part?

 

[pierpoljam]

Calcium chloride, sodium carbonate, and magnesium chloride

 

[Randy Holmes-Farley]

Calcium chloride and sodium carbonate

What recipe? I’m just trying to understand why you have an unbalanced usage.

 

[pierpoljam]

RS Bulk 2-part *true purity dosing system (makes 10 x 1 gallon - 5/5)

Bulk 2-part dosing system (makes 10 x 1 gallon)

www.reefsupplies.ca

 

[Randy Holmes-Farley]

that two part is a bad design that is not even close to 1:1 dosing. It has way too much alk to calcium.

 

[pierpoljam]

Many thanks for the answer Randy. Could you point out some ressources to remake the calculations?

 

[pierpoljam]

that two part is a bad design that is not even close to 1:1 dosing. It has way too much alk to calcium.

Hi , based on the post

DIY Three Part with Balling Part C Recipe​

I should dose 594g per gallon of bicarbonate cooked in soda ash. I assume cooking would lower the masse of the resulting soda ash being disolved. The reefsupplies recipe is 475 g per gallon soda ash.

 

[pierpoljam]

After searching on internet mole ratio of NaHCO3 to Na2CO3 would be 1:2 so if I dissolve 297g of soda ash instead of the recommended 475g . Would that correct the ratio of the 2 part ?

 

[Randy Holmes-Farley]

After searching on internet mole ratio of NaHCO3 to Na2CO3 would be 1:2 so if I dissolve 297g of soda ash instead of the recommended 475g . Would that correct the ratio of the 2 part ?

I’ll go over the math in a bit.

 

[Randy Holmes-Farley]

OK, let's look at the math.

500 g of calcium chloride dihydrate (molecular weight 147 g/mole; it is the most likely type of calcium chloride to use), contains 3.4 moles of calcium.

We want to match that with about 3.4 moles of carbonate (actually, a little bit more since we are not making exactly calcium carbonate in a reef tank, but let's ignore that minor correction).

Sodium carbonate has a molecular weight of 106 g/mole, so 3.4 moles is 360 grams of sodium carbonate.

That makes a balanced two part with the same balance as kalkwasser or All For Reef, all of which add a tiny bit too much calcium relative to alk due to magnesium replacing some of the calcium in calcium carbonate.

 

[AKReefing]

Hi , based on the post

DIY Three Part with Balling Part C Recipe​

I should dose 594g per gallon of bicarbonate cooked in soda ash. I assume cooking would lower the masse of the resulting soda ash being disolved. The reefsupplies recipe is 475 g per gallon soda ash.

I wonder if I misread your post. Baking soda (sodium bicarbonate) can be baked in an oven at 300 degrees Fahrenheit for an hour to create soda ash (sodium carbonate). See Randy's recipe/instructions here: https://reefkeeping.com/issues/2006-02/rhf/index.php

 

[Randy Holmes-Farley]

I wonder if I misread your post. Baking soda (sodium bicarbonate) can be baked in an oven at 300 degrees Fahrenheit for an hour to create soda ash (sodium carbonate). See Randy's recipe/instructions here: https://reefkeeping.com/issues/2006-02/rhf/index.php

Like a turkey, low temps can take longer and longer while a high temp goes faster and it cannot be overcooked in a home oven.

 

[Garf]

high temp goes faster and it cannot be overcooked in a home oven.

Oh yes it can, sometimes catastrophically.

 

[AKReefing]

Oh yes it can, sometimes catastrophically.

What catastrophe did you personally experience when baking baking soda?

 

[Garf]

What catastrophe did you personally experience when baking baking soda?

To clarify, I've never over cooked baking soda, but I have burnt a turkey. Sorry for any confusion

 

[rishma]

“When Calcium, Alkalinity and Magnesium Demand Does not Balance”

usually translates as….

“When calcium, magnesium and alkalinity dosing is not balanced”

 

[Randy Holmes-Farley]

To clarify, I've never over cooked baking soda, but I have burnt a turkey. Sorry for any confusion

lol.

 

[AKReefing]

To clarify, I've never over cooked baking soda, but I have burnt a turkey. Sorry for any confusion

Tomato, baking soda.