Raising Alkalinity with baking soda question

[Scott.h]

So that I'm understanding this correctly.. unbaked baking soda is sodium bicarbonate, and baked baking soda is sodium carbonate? And unbaked soda slightly lowers ph, while baked soda raises ph?

If this is correct, with my ph 8.2, and wanting to bump my alkalinity from 7 to 7.5 in my top off water what would be my best approach, how much would I add, and over how long a period would I add that water?

 

[Myka]

You're right on the bicarb vs carb.

If I were you I would use bicarb. There are plenty of reef chemistry calculators to use to help you figure out how much to dose. I don't like to change alkalinity more than 0.5 dKH per week if you're moving from your typical alkalinity to a new target - especially if your tank is ULN or if the alkalinity has been very stable for a long time.

http://reef.diesyst.com/chemcalc/chemcalc.html

 

[Downbeach]

So that I'm understanding this correctly.. unbaked baking soda is sodium bicarbonate, and baked baking soda is sodium carbonate? And unbaked soda slightly lowers ph, while baked soda raises ph?

This is true, but the affect is temporary. Baking soda has a bit of CO2 in it, so has a pH lowering affect when added to your system. When you bake the baking soda, you're driving off the CO2, as a result, will have a slight pH raising affect when added to your system. In both cased when the CO2 in your system reaches equilibrium with the surrounding atmosphere, through gas exchange, your pH will return to its base level.

If this is correct, with my ph 8.2, and wanting to bump my alkalinity from 7 to 7.5 in my top off water what would be my best approach, how much would I add, and over how long a period would I add that water?

I would use the calculator Myka provided, fill in the blanks for your system, and select Randy's recipe #2 for Alkalinity, from the drop down menu.

Here is the recipe how to's:

http://reefkeeping.com/issues/2006-02/rhf/index.php#11

Plain baking soda can be a bit difficult to get into solution, so I used to use a hand held blender to help. Heating the mixture will also help.

 

[Scott.h]

Thank you both. I've never had to raise alk due to my previous salt, and was intentionally lowering it before switchinga few months ago. Now I'm watching it creep too low and was just planning ahead, even if Im just adding 1/4 teaspoon a day in with a half gallon of water.

 

[Myka]

Thank you both. I've never had to raise alk due to my previous salt, and was intentionally lowering it before switchinga few months ago. Now I'm watching it creep too low and was just planning ahead, even if Im just adding 1/4 teaspoon a day in with a half gallon of water.

You're welcome.

Do you have a doser or will you be dosing manually? If you're dosing manually and the demand is low as it sounds, then I'd suggest you just use one of the pre-mixed liquid 2-part products. I like Tailored Aquatics for this.

 

[Randy Holmes-Farley Verified Community Expert]

Is the pH always 8.2 day and night? Most people are lower night than day, so I'd probably dose baked baking soda in the late pm or early am, but I doubt your notice any apparent difference whichever you dose, especially for the rare times of dosing in this situation.

 

[Scott.h]

I am doing everything manually this far. I'm considering a Neptune apex system and dosing pumps, but honestly 85 gallons of water is no sweat to maintain manually. And I know that manually dumping in x does x. I'm afraid if I jump to calcium reactors and such I might create a mess.
My salt has has been 7.5 dkh which is perfect for my vodka dosing, but this bucket is lower for some reason which kind of stinks.

 

[Scott.h]

I am doing everything manually this far. I'm considering a Neptune apex system and dosing pumps, but honestly 85 gallons of water is no sweat to maintain manually. And I know that manually dumping in x does x. I'm afraid if I jump to calcium reactors and such I might create a mess.
My salt has has been 7.5 dkh which is perfect for my vodka dosing, but this bucket is lower for some reason which kind of stinks.

You're welcome.

Do you have a doser or will you be dosing manually? If you're dosing manually and the demand is low as it sounds, then I'd suggest you just use one of the pre-mixed liquid 2-part products. I like Tailored Aquatics for this.

 

[Scott.h]

Is the pH always 8.2 day and night? Most people are lower night than day, so I'd probably dose baked baking soda in the late pm or early am, but I doubt your notice any apparent difference whichever you dose, especially for the rare times of dosing in this situation.

That was my thoughts exactly. If I do it at 6 o'clock in the morning my ph shouldn't go higher then 8.2 anyway. Now at the same time if I cocktail the two together, carbonate and bicarbonate, wouldn't that offset the pH difference anyways?

 

[Myka]

Fwiw, the Tailored Aquatics Alkalinity part is both carb and bicarb.

 

[Randy Holmes-Farley Verified Community Expert]

That was my thoughts exactly. If I do it at 6 o'clock in the morning my ph shouldn't go higher then 8.2 anyway. Now at the same time if I cocktail the two together, carbonate and bicarbonate, wouldn't that offset the pH difference anyways?

Yes, although people overthink this. IMO, just carbonate is best for most folks. The magic ratio that has no effect on pH is mostly bicarbonate and a little carbonate, but it varies with the pH that you are at.

 

[Jgao]

This is true, but the affect is temporary. Baking soda has a bit of CO2 in it, so has a pH lowering affect when added to your system. When you bake the baking soda, you're driving off the CO2, as a result, will have a slight pH raising affect when added to your system. In both cased when the CO2 in your system reaches equilibrium with the surrounding atmosphere, through gas exchange, your pH will return to its base level.



I would use the calculator Myka provided, fill in the blanks for your system, and select Randy's recipe #2 for Alkalinity, from the drop down menu.

Here is the recipe how to's:

http://reefkeeping.com/issues/2006-02/rhf/index.php#11

Plain baking soda can be a bit difficult to get into solution, so I used to use a hand held blender to help. Heating the mixture will also help.

Hey Downbeach,

I've been researching this recipe but I can't seem to find any Dowflake, is the product discontinued? Is there an alternative method to creating cheap Calcium parts?

 

[Downbeach]

Hey Downbeach,

I've been researching this recipe but I can't seem to find any Dowflake, is the product discontinued? Is there an alternative method to creating cheap Calcium parts?

It can be hard to come by, especially in certain parts of the country. I was using the calcium chloride from BRS. After a while, I got lazy and started to buy the soda ash there too.

 

[Randy Holmes-Farley Verified Community Expert]

Yes, BRS and Dr Foster and Smith sell bulk now.

Some people use pool brands, such as Leslie's, but I've not tested it.

 

[jnw240reef]

5# bag from sams/Costco