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 chemistry classes!

 

[usmcmarc]

I've had good results from Kent Tech CB 2 Part Calcium Buffer. IME it effects your Calcium, dKh and pH.

 

[ccCapt]

Baking soda is perfectly fine for raising your alk (it will also slightly lower your pH). You should test your alk the same time every day. pH has a slight affect on alk, so if you test one day in the AM when your pH will be typically lower, you will get a different reading than if you test it mid afternoon when the pH is up.
FYI, if your tank is using alot of alk, it is also using alot of ca and mag. All 3 are used up proportionally. You can save some $ and make your own alk, ca and mag supplements. I've been doing this for years. http://reefkeeping.com/issues/2006-02/rhf/index.php

 

[MarineFlake]

I think my surprise comes from how much I am having to dose. Its like 3 table spoons every day to every other day. Mg and Ca are fine. Its only a 75G tank and is mostly soft corals. Something is up and I think it has to do with the balance of carbonates and borate. Im going to order the super buffer again and compare its performace with the baking soda.

 

[MarineFlake]

As a note, someone on another board mentioned they bake the soda before using it...I am looking into why and if maybe I am not dosing it properly. I have been using it right out of the box mixed with RO/DI water.

 

[cmor1701d]

You might want to read http://www.advancedaquarist.com/issues/april2004/chem.htm

"Spread baking soda (594 grams or about 2 ¼ cups) on a baking tray and heat in an ordinary oven at 300 °F for 1 hour to drive off water and carbon dioxide" as opposed to using washing soda.

That's from the older version of the article that ccapt linked.

 

[MarineFlake]

Indeed I have read the same article(s). It seems baking the soda provides for higher PH and mixing it with out baking it results in a slightly depressed PH. I have been adding it incorrectly as well. I need to drip it in over time rather than dumping a batch in. I still believe that borate will assist in the PH swings which is why its included in the manufactured version. Just takes more and more reading!!

Thanks!