Buffering PH

[randygsx]

PS, you SHOULD stop drinking soda-pop. The carbonic acid and the phosphorus compounds (including phosphoric acid) lower your blood's pH, causing your bones to leach calcium into your bloodstream as a buffer. The caffeine added has been proven to cause nearly as much damage to the major arteries as cocaine, which basically shreds the aorta (figuratively).

 

"In addition to cavities, heavy pop consumption has been linked to diabetes, obesity, kidney stones, heart disease and osteoporosis."

 

http://www.modental.org/YourDentalHealth/StopthePop.aspx

 

"Animal studies demonstrate that phosphorus, a common ingredient in soda, can deplete bones of calcium."

 

http://www.mercola.com/2001/mar/10/soda_pop_dangers.htm

But what do I know?

 

LOL omg, you try to equate carbonic acid with battery acid and now upon being called out, try to divert the argument into an "oh it's bad anyways..." argument with caffeen and the sugar found in soda? GIVE ME A BREAK!

 

~randy

[frag]

Schwazreef:

 

I am concerned that we may have just confused the issue for you. I use Kalk as a buffer in one of my tanks and I use wash soda in the others. I have also used sodium bicarbonate for extended periods. I guess it is up to you to sort through the BS. Perhaps research from outside media will be the key. Good luck with your tank, it looks like you are on the right track.

[Schwazreef]

Frag. Thanks, but no cofusion here. I appreciate an in depth answers/discussion. I have stated adding Kalk to my top off as of last fridays water change in an attempt to keep my ph up as weel as utilize the other benefits Ive seen cited.

 

Wondering perhaps what other people mix up per gal. 1/8 - 2 teaspoons(?) seems kins vague. Keep in mind I have only a few stonies, im under the impression that makes a difference.

[Caesar777]

randy - Chill out. I realized my mistake on the acid. Gosh, didn't I mention that already? The soda thing was true, but nevertheless a half-joke. Have a sense of humor. YOU can't admit when YOU'RE wrong. The point still stands: baking soda lowers pH. The end.

[bobioden]

I just want to know where you read that Baking Soda= Battery Acid.

 

Bob

[Caesar777]

Duhh, that part was a mistake; I mentioned that already. People make mistakes--even me, as godlike as I am. And granted, battery acid (sulfuric acid) is a strong acid (not in strength/molarity but as far as molecular bonds/structure) and carbonic acid is only a weak acid, but the latter IS formed from adding sodium bicarbonate to the tank water, AND it WILL lower pH. But you can't accept that part? You can't just say, "Oh, my mistake, alright, then"... You have to go on about a mistake I made when posting right before work without time to verify that part? Sheesh. SOME people are hard-headed, eh?

[bobioden]

Not a problem, sorry I missed where you said it was a mistake.

 

 

 

Bob

[Adamd]

baking soda lowers pH. The end.

 

 

True. That's why you add Washing soda.

[MrAnderson]

Either way, buffers tend to stabilize whatever pH a tank equilibrates at based on bioload and dissolved CO2. If the problem is low pH then it should be addressed by aeration or macroalgae to change these variables. Buffers aren't meant to solve that problem long term. Yes, they might change pH transiently, but once all the reactive groups forming the newly imbalanced acid-base equilibrium sort out based on the existing (possibly metabolic) ionic imbalance that caused the low pH in the first place, then you'll be back to square one. IMO.

 

However, there's no substitution for CaCO3 consumption by calcifying organisms, hence the need for baking soda for that purpose. But in my mind that's a separate issue, others may differ.

 

Just add some macroalge or open a window. More "biological" anyhow and much less work, once the system is tuned.

[Andy Somnifac]

The point still stands: baking soda lowers pH. The end.

 

Then I have a question, and I don't mean to be argumentative. If this is the case, baking soda lowering pH, then why does it increase the pH of my tap water? I use baking soda and epsom salts when I do water changes for my cichlid tanks, and the addition of the substances bring my pH from about 7.2 out of the tap to about 8.0, where it remains stable.

[MrAnderson]

Then I have a question, and I don't mean to be argumentative. If this is the case, baking soda lowering pH, then why does it increase the pH of my tap water? I use baking soda and epsom salts when I do water changes for my cichlid tanks, and the addition of the substances bring my pH from about 7.2 out of the tap to about 8.0, where it remains stable.

 

I think she meant it lowers the pH of seawater. Freshwater chemistry is very different.

 

It's generally known that baking soda has a slight lowering effect on the pH in seawater. This is illustrated here in a reef chemistry calculator, where the pH effects of various additives can be calculated.

[Andy Somnifac]

Gotcha.

[Blind Tree Frog]

I was wondering how a base was making the water more acidic.

[Caesar777]

Chemical reactions. Remember that everything is made up of chemicals, and these chemicals react with each other depending on how they're bonded and many other things.

[MrAnderson]

I was wondering how a base was making the water more acidic.

 

Because bicarbonate dissociates into carbonate and hydrogen ion. Any increase in hydrogen ion concentration is a drop in pH.

 

HCO3- > H+ + CO3--

 

This effect can be exaggerated by the extant CO2 levels and pH.

[horseflesh]

Here is another Holmes-Farley article that discusses the relationship between alk and pH. Scroll down to "Alkalinity Supplements" for the summary.

 

http://www.advancedaquarist.com/issues/may2002/chem.htm

 

For this discussion, let’s presume that we want to supplement the carbonate alkalinity of a reef tank. That is, in the end we want to increase the bicarbonate and carbonate levels in the tank. There are a variety of ways to achieve this end, and these different ways have different immediate impacts on pH. Three of these ways (and combinations thereof) are fairly common in reefkeeping. These ways are addition of bicarbonate, carbonate, and hydroxide. In a reef tank that is permitted to equilibrate its total CO2 levels with the atmosphere, these additions all end up with the same final pH. That is, it is only the amount of alkalinity added that determines the final pH, not the nature of the additive itself.

 

In the short term, however, the impact on pH is very different... (table deleted) ...

 

From this data it is clear to see the large increase in pH caused by the addition of hydroxide, and also the significant increase when using carbonate.

Bicarbonate, on the other hand, shows the expected slight decrease in pH

, but not nearly as much as is found with a strong acid of equal concentration.

It is also clear that after sufficient time to equilibrate with atmospheric CO2, these differences disappear, and the pH is the same for all of the 0.5-meq/L alkalinity additions. This is an important result: in seawater in equilibrium with the atmosphere, for a given alkalinity there is a single pH that results, regardless of what was added to get to that alkalinity.

 

Edit: Just before the end there look for "Bicarbonate Addition" where he addresses our hot topic in more detail.