carbonate/bicarbonate

[MarineFlake]

So I have been using baking soda for a bicarbonate for the last week. Its not been very stable. 11.3 dKH one night, 9.3 the next morning. I looked at the ingredients for my favorite Kent brand dKH powder and it lists carbonates and borate. I can only assume this helps stabilize the solution. Anyone know of a safe carbonate additive off the shelf? As it stands, it looks like Im going to re-up my order for next year to include more Kents though I was hoping for a more readily available dKH alternative. Maybe its time to register for some Univ of Mem chemistry classes!

[Codeman00]

What kind of test kits are you using?

How does the dKH vary over time? I know you said that one night it is 11.3 and the next morning its 9.3 but what is the next night? And the next morning? What about the measurements for a week (day and night) Does it go back up or down? Two measurements really isn't enough information for us to help.

When do you add baking soda? How often?

[MarineFlake]

Well, this evening it was lower still. Doing some more reading, it looks like my initial theory is correct. Borate does help buffer against PH swings as well as the ALK itself. Unless I can come up with my own bicarbonate/carbonate/borate solution, looks like Im going to re up my superbuffer order.

[Reefdiver77]

I slow drip baking soda solution (baked in oven first) in a DIY bottle with tubing and thumb controller. I follow the reef chemistry calculator on RC to decide what concentration and over what period to drip it. I took 4 college chemistry classes and it is still Greek to me!!

[MarineFlake]

Bake? Please go on with this baking thing...I don't seem to recall anyone mentioning that they bake their soda before mixing and adding...

[scarson61]

Baking just burns off excess h2o. Here is an article about making 2 part that has 2 recipes one with baking the baking soda and one with out baking it. (it has to do with your pH levels)

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

[MarineFlake]

Yes, thanks, I have read both article(s). I came to the same conclusion that baking the soda results in a slightly higher PH and not baking it yields a slightly depressed PH. I do now realize that I have been dosing it incorrectly however. I need to drip it in rather than add it all at once. I still think that the borate plays an important role in the over all PH swing which would be why the manufactured version includes it. The more I read the more I understand this is not the same as using Superbuffer and indeed takes some trial and error.

Thanks!!