calcium and carbonate buffer.

nicholasb · 03/05/2014, 12:38 AM

Hi!!. I have been keeping marine fish for 3.5 years and hard corals for 2.5 years.
as I understand it, if you add calcium and carbonate 2 part to a reef tank, then they should ballance each other out, as the hard corals take up calcium and carbonate in a balanced way.
Some one once told me that calcium and carbonate buffer each other out, is this possible. I thought that the carbonate/alkalinity was the buffer, and calcium from a 2 part had no direct affect on the carbonate when added (asumming there is no precipitation).
Or would it be possible to say that when you add carbonate/alkalinity to a tank, it buffers with the calcium already in the tank.
Is calcium chloride from a 2 part P.H.7, and so does not buffer anything ?.
I have read many articals by Randy Holmes Farley, but can find nothing to support this. (Randy's articals are very usfull!!)

Many thanks to any one with a bit of chemisty knowlege

disc1 · 03/05/2014, 08:11 AM

The calcium chloride in the two part shouldn't have any great effect on pH.

I can't answer the rest because I'm not quite sure what you think the word buffer means.

nicholasb · 03/05/2014, 09:51 AM

To me the word buffer is simply saying it buffers, or stops a p.h swing. So both would stop/buffer a swing of the other some how. But what it means to the person who said that "calcium buffers carbonate", I don't quite know!!!.

nicholasb · 03/05/2014, 09:58 AM

To me the word Buffer is somply saying it buffers or stops a P.H swing. So both would stop/buffer a swing of the other some how. But what it means to the person who said that "calcium buffers carbonate", I don't quite know.
Thanks for saying the calcium choride shouldn't affect the P.H, thats what I thought.

disc1 · 03/05/2014, 10:42 AM

Buffer in chemistry has a particular definition. It is a mixture of a weak acid or base with its conjugate. Solutions made this way are called buffers and they tend to resist changes in pH.

bertoni · 03/05/2014, 02:35 PM

"Calcium buffers carbonate" makes no sense in any definition of the term "buffer".

nicholasb · 03/05/2014, 06:47 PM

Thank you so much for your reply. I couldn't understand myself how one could buffer the other, it would mean they would both have to be buffers!!.

tmz · 03/05/2014, 09:06 PM

The alkalinity buffers pH swings. The calcium does not and doesn't effect the carbonate alkalinity outside of precipitation as calcium carbonate.

nicholasb · 03/05/2014, 11:10 PM

Yes tanks. You clearly know what you are talking about!!.

03/05/2014, 12:38 AM	#1
nicholasb Registered Member Join Date: Mar 2014 Location: south west england Posts: 292	calcium and carbonate buffer. Hi!!. I have been keeping marine fish for 3.5 years and hard corals for 2.5 years. as I understand it, if you add calcium and carbonate 2 part to a reef tank, then they should ballance each other out, as the hard corals take up calcium and carbonate in a balanced way. Some one once told me that calcium and carbonate buffer each other out, is this possible. I thought that the carbonate/alkalinity was the buffer, and calcium from a 2 part had no direct affect on the carbonate when added (asumming there is no precipitation). Or would it be possible to say that when you add carbonate/alkalinity to a tank, it buffers with the calcium already in the tank. Is calcium chloride from a 2 part P.H.7, and so does not buffer anything ?. I have read many articals by Randy Holmes Farley, but can find nothing to support this. (Randy's articals are very usfull!!) Many thanks to any one with a bit of chemisty knowlege

03/05/2014, 08:11 AM	#2
disc1 -RT * ln(k) Join Date: Sep 2010 Location: Little Rock Posts: 9,705	The calcium chloride in the two part shouldn't have any great effect on pH. I can't answer the rest because I'm not quite sure what you think the word buffer means. __________________ David Current Tank: Undergoing reconstruction...

03/05/2014, 09:51 AM	#3
nicholasb Registered Member Join Date: Mar 2014 Location: south west england Posts: 292	Buffer To me the word buffer is simply saying it buffers, or stops a p.h swing. So both would stop/buffer a swing of the other some how. But what it means to the person who said that "calcium buffers carbonate", I don't quite know!!!.

03/05/2014, 10:42 AM	#5
disc1 -RT * ln(k) Join Date: Sep 2010 Location: Little Rock Posts: 9,705	Buffer in chemistry has a particular definition. It is a mixture of a weak acid or base with its conjugate. Solutions made this way are called buffers and they tend to resist changes in pH. __________________ David Current Tank: Undergoing reconstruction...

03/05/2014, 02:35 PM	#6
bertoni RC Mod Join Date: Mar 2002 Location: Mountain View, CA, USA Posts: 88,616	"Calcium buffers carbonate" makes no sense in any definition of the term "buffer". __________________ Jonathan Bertoni

03/05/2014, 09:58 AM	#4
nicholasb Registered Member Join Date: Mar 2014 Location: south west england Posts: 292	To me the word Buffer is somply saying it buffers or stops a P.H swing. So both would stop/buffer a swing of the other some how. But what it means to the person who said that "calcium buffers carbonate", I don't quite know. Thanks for saying the calcium choride shouldn't affect the P.H, thats what I thought.

03/05/2014, 06:47 PM	#7
nicholasb Registered Member Join Date: Mar 2014 Location: south west england Posts: 292	Thank you so much for your reply. I couldn't understand myself how one could buffer the other, it would mean they would both have to be buffers!!.

03/05/2014, 09:06 PM	#8
tmz ReefKeeping Mag staff Join Date: Apr 2006 Location: West Seneca NY Posts: 27,691	The alkalinity buffers pH swings. The calcium does not and doesn't effect the carbonate alkalinity outside of precipitation as calcium carbonate. __________________ Tom Current Tank Info: Tank of the Month , November 2011 : 600gal integrated system: 3 display tanks (120 g, 90g, 89g),several frag/grow out tanks, macroalgae refugia, cryptic zones. 40+ fish, seahorses, sps,lps,leathers, zoanthidae and non photosynthetic corals.

03/05/2014, 11:10 PM	#9
nicholasb Registered Member Join Date: Mar 2014 Location: south west england Posts: 292	Yes tanks. You clearly know what you are talking about!!.