Making Sodium Carbonate from Sodium Bicarbonate- guidance requested

[Bill_Moorman]

Good evening all!

I typically purchase a 1 gallon soda ash mix from BRS. However, I have a jug (olden days!) of BRS Sodium Bicarbonate that I have never used. I saw on melvsreef a writeup that shows you can bake bicarbonate at 300 degrees for an hour to turn it into soda ash. I plan on doing so tonight, has anyone had experience doing so? I read that after baking it, the ratio is 2 cups to 1 gallon of water. Does that seem correct? I generally use it for two part dosing.

What I am most concerned about is ensuring the concentration of the DIY soda ash is equal to the BRS Soda Ash mix so that when I dose, the measurements are accurate for what I need to dose to up the Alk according to the BRS calculator.

 

[MJ in Boise]

Baking time is correct. Soda ash is soda ash. Use the brs calculator and it will work fine. Spread it thin and bake.

 

[Randy Holmes-Farley Verified Community Expert]

BRS uses my recipe (Recipe 1) which is detailed here:

http://reefkeeping.com/issues/2006-02/rhf/index.php

 

[Randy Holmes-Farley Verified Community Expert]

Note that you cannot overbake it, but like a turkey, if you are heating a lot it can take a long time for the inside to reach temp. So longer and hotter than my original plan cannot hurt and may help convert it all. That won’t change the alkalinity, just the pH raising effect and how easily it dissolves in fresh water.

 

[Bill_Moorman]

Thanks Randy! How can you tell when it's "done?" I baked 2 cups last night at 300 for an hour, and I did a cup this morning for the same time, but I really don't have a metric to know when it's fully done. Also, what I am reading is that using your recipe, 594 grams should be dissolved into 1 gallon of RO/DI to make Alkalinity supplement. Is that still accurate?

 

[Randy Holmes-Farley Verified Community Expert]

Thanks Randy! How can you tell when it's "done?" I baked 2 cups last night at 300 for an hour, and I did a cup this morning for the same time, but I really don't have a metric to know when it's fully done. Also, what I am reading is that using your recipe, 594 grams should be dissolved into 1 gallon of RO/DI to make Alkalinity supplement. Is that still accurate?

That is the recipe, yes. Weight before baking, not after.. If you have a scale, 375 grams after baking is totally done. Won't matter if it is mostly done.

 

[Bill_Moorman]

That is the recipe, yes. Weight before baking, not after.. If you have a scale, 375 grams after baking is totally done. Won't matter if it is mostly done.

Perfect. I have a ton of baking soda from the old BRS jug, so as not to chance it, I am restarting. 594 grams before baking, set at 300 for 1.5 hours. I'll keep baking until I get to 375 grams, and then add that to 1 gallon of freshwater. Thank you again for your help!

 

[Randy Holmes-Farley Verified Community Expert]

Perfect. I have a ton of baking soda from the old BRS jug, so as not to chance it, I am restarting. 594 grams before baking, set at 300 for 1.5 hours. I'll keep baking until I get to 375 grams, and then add that to 1 gallon of freshwater. Thank you again for your help!

You'll go faster at 400 deg F.

 

[Bill_Moorman]

You'll go faster at 400 deg F.

Right on! Thank you!

 

[PatW]

Bulk Reef Supply adds 2.5 cups of soda ash or calcium chloride to 1 gallon of RODI. Of course, you could add just 2 cups to a gallon of RODI. You would just need to divide by .8 for the amount needed in the BRS calculator.