Creating and using Sodium carbonate

Myka · Mar 7, 2017

I'm making DIY Aquaforest balling solutions.

The recipe calls for 80g Aquaforest KH Buffer (which is NaHCO3 Sodium bicarbonate) per 1L H2O. I asked AF if there is anything besides NaHCO3 in the KH Buffer, they replied it is pure NaHCO3.

I measured out 80g x 2.5 (I made 2.5L of solution) NaHCO3, baked it, and used it. Apparently this is incorrect as the alkalinity is not maintaining though calcium is. Alk is falling BAD, so obviously the amount is WAY off. I've not tried substituting Na2CO3 in a NaHCO3 recipe before, so I'm not sure what's going on here.

Looking through Randy's Recipes, I note that RR#1 uses 594 grams NaHCO3, then bake it to create Na2CO3. RR#2 uses 297 grams NaHCO3. In the notes it says most tanks will use about 2x the volume of RR#2 than RR#1. 594 grams NaHCO3 in RR#1 is exactly twice the NaHCO3 used in RR#2 so that makes sense.

So in my brain this morning, it seems to me that my method of measuring out the proper amount of NaHCO3, then baking it should equal the proper amount of Na2CO3 to make the same strength recipe, shouldn't it? Baking the NaHCO3 shouldn't make it less potent, should it?

Maybe I simply fudged the recipe when I built it??

Randy Holmes-Farley · Mar 7, 2017

Baking does not at all change the alk in the sodium bicarbonate. It just drives off CO2.

The demand for alk will depend on both the alk and the pH, and so if you boost pH you would expect more demand.

revhtree · Mar 7, 2017

Randy Holmes-Farley said:
Baking does not at all change the alk in the sodium bicarbonate. It just drives off CO2.

The demand for alk will depend on both the alk and the pH, and so if you boost pH you would expect more demand.

So the higher PH will cause more ALK demand?

Randy Holmes-Farley · Mar 7, 2017

revhtree said:
So the higher PH will cause more ALK demand?

Yes. Both calcification by some corals and abiotic precipitation are faster at higher pH.

In terms of precipitation likelihood, a rise of 0.3 pH units is similar to a doubling of alk or calcium.

Myka · Mar 7, 2017

Randy Holmes-Farley said:
Baking does not at all change the alk in the sodium bicarbonate. It just drives off CO2.

Ok, that's what made sense to me! So I must have messed up my measuring.

Ca and Mg are staying steady, and alk just keeps falling - like over 1 dKH per day. I just mixed up a new batch, that must be the issue. Ugh...

Thank you for clarifying!

bhavy · Mar 7, 2017

So which recipe did you end up using and and how much are u dosing each day?
Did that stop your ALK from dropping?

Myka · Mar 8, 2017

bhavy said:
So which recipe did you end up using and and how much are u dosing each day?
Did that stop your ALK from dropping?

If you read my first post, you will see the recipe I'm using. I'm using the Aquaforest recipe to make DIY Components 1+2+3+ which Aquaforest provides the ingredients for.

At this moment I'm baking a new batch of Sodium bicarbonate in the oven, and will mix up a new #2 container. I'm using the same amount of bicarb that I remember using last time though, so I'm starting to doubt if I mis-measured last time or not. I don't think I did.

I have been using the pre-packaged Aquaforest Components 1+2+3+ for almost a year, and decided to switch to the "mix it yourself" version because it is much cheaper. The "mix it yourself" version is supposed to be the same concentration as the pre-mixed version. Randy's Recipe #1 is about 1.8 times more concentrated than the Components just going off the amount of bicarb used to make the recipes. Components is 80g per liter of water, and RR#1 is 156g per liter of water. I'm dosing 45 mL per day Components and currently I'm adding about 1 tsp bicarb per day on top of this.

Myka · Mar 8, 2017

I found the problem!!! The doser was turned off!!!! I can't see the face of the doser how I have it positioned, and I didn't actually check it. Wow...I guess I better go check all the params again! It's all so clear now...

...can't see the forest for the trees.

Randy Holmes-Farley · Mar 8, 2017

Myka said:
Ok, that's what made sense to me! So I must have messed up my measuring. Ca and Mg are staying steady, and alk just keeps falling - like over 1 dKH per day. I just mixed up a new batch, that must be the issue. Ugh...

Thank you for clarifying!

Or the demand is higher and you need to dose more. At 1 dKH alk drop, you'd be hard pressed to detect the accompanying calcium drop and will never see any change in magnesium demand with a hobby kit.

Myka · Mar 8, 2017

Randy Holmes-Farley said:
Or the demand is higher and you need to dose more. At 1 dKH alk drop, you'd be hard pressed to detect the accompanying calcium drop and will never see any change in magnesium demand with a hobby kit.

Yes, you are absolutely correct. I just tested ca, alk, Mg, and K. The differences in Ca, Mg, and K were negligible compared to 2 weeks ago. Alk after dosing 1 tsp bicarb this morning is sitting at 7.0 dKH. So now that the doser is actually functioning (ugh), this number should stay steady. I'm just going to leave it there for at least a week before considering to bump it up a little more. Some Acros have definitely paled during this fiasco.

Myka · Mar 9, 2017

The most amazing thing has happened in the last 24 hours! Alkalinity has maintained without "additional" manual dosing! Astounding what can happen when the doser is switched back on!

Lesson for everyone: If it doesn't make sense, check the basics.

Randy Holmes-Farley · Mar 9, 2017

Myka said:
The most amazing thing has happened in the last 24 hours! Alkalinity has maintained without "additional" manual dosing! Astounding what can happen when the doser is switched back on!

Lesson for everyone: If it doesn't make sense, check the basics.

lol

Happy Reefing.