Reef Aquarium Fact #168 Calcium isn't the limiting factor in calcification; it's the saturation of a

[revhtree]

We are going to continue discussing the reef aquarium facts submitted by our members. Do you agree or disagree? What are your thoughts?

Fact #168

Contrary to popular belief, calcium isn't the limiting factor in calcification; it's the saturation of aragonite in the water. If the saturation is above 3, calcification can happen faster than it does in NSW.

How is this useful? Possible uber-growth. Saturation is directly linked to alkalinity, PH, and calcium. Anytime any of those increase, so does the saturation. Calcium carbonate will dissolve in water with a saturation less than 1. If it's above 1, it's supersaturated and calcification can happen. If the saturation is below the NSW level of 3 but >1, hard coral growth is just really slow. A tank in a basement with a ph of 7.7, 410 calcium and 2.5 alk (meq/l) only has a saturation of 1 and SPS growth would be practically impossible until the ph is in a normal range. If the aquarist put some ventilation in and corrected the ph to a normal 8.2, the saturation would be 3. If an aquarium had a calcium level of 820, alk of 2.5 and ph of 8.2, the saturation would be 2x that of NSW! That doesn't necessarily "snow storm" either. Your SW right now is supersaturated; it doesn't precipitate because of the magnesium and phosphorous that bind the calcium into the water. If the magnesium was increased proportionally (3.25x) to the ca and a sound temp and ph was kept, a snowstorm would be unlikely. The growth could [theoretically] be wicked.

See The Reef Aquarium, Volume 3 pages 241-245

Truth or False? What else might we need to learn on this subject? Please also share any pictures that may pertain to the subject.

 

[wysiwyg]

i would agree i have a 3" aragonite bed and have a ton of calcification on everything with calc lvl of around 550-600

 

[lpslover]

Interesting. Is there a formula/equation for figuring your saturation?

 

[Young Frankenstein]

Could someone explain in construction language ?

 

[Steelerfan747]

Interesting topic. Thanks for sharing

 

[Young Frankenstein]

Could someone post a link i cant find it See The Reef Aquarium, Volume 3 pages 241-245

 

[Young Frankenstein]

I need this explained please.

 

[Young Frankenstein]

Trying hard to find something explaining this post Aquarium Chemistry: The Chemical and Biochemical Mechanisms of Calcification — Advanced Aquarist | Aquarist Magazine and Blog

 

[Young Frankenstein]

This a big statement Revhtree .......still searching other articles, but I want to "get to the bottom of this" What is that Precipitate in My Reef Aquarium? by Randy Holmes-Farley - Reefkeeping.com

 

[Young Frankenstein]

i would agree i have a 3" aragonite bed and have a ton of calcification on everything with calc lvl of around 550-600

Yes but thats not what this thread is saying basically he increases Ph and Ca and Alk and to avoid precipitation he also increases MG. Mg is the limiting factor to precipitation, but iron, temperature also play a role. All I can say this needs further analysis by the author, and has anyone try this ?

 

[Young Frankenstein]

Maybe if someone can get Beaker Bob we can get some helpful explaining.

 

[Young Frankenstein]

This is not a fact unless someone can prove it ........ I do believe there is a method thats why i am asking. Lets start from scratch ........... does anyone here keep their tank above NSW parameters ?

 

[Young Frankenstein]

Ok ok I understand ............. I will just have to find out myself by experimenting ........... Revhtree I wont ask anything else on this LOL

 

[WRXgucci]

This is not a fact unless someone can prove it ........ I do believe there is a method thats why i am asking. Lets start from scratch ........... does anyone here keep their tank above NSW parameters ?

Some one please chime in on more info!! This is very interesting and I would like to know how to calculate this.

 

[robert]

This article is worth a read. Not the direct object of the study - but on point.




Effect of calcium carbonate saturation of seawater on coral
calcification
J.-P. Gattuso b a,) , M. Frankignoulle b, I. Bourge b, S. Romaine a , R.W. Buddemeier c

The carbonate chemistry of seawater is usually not considered to be an important factor influencing calcium-carbonate-
precipitation by corals because surface seawater is supersaturated with respect to aragonite. Recent reports, however, suggest
that it could play a major role in the evolution and biogeography of recent corals. We investigated the calcification rates of
five colonies of the zooxanthellate coral Stylophora pistillata in synthetic seawater using the alkalinity anomaly technique.
Changes in aragonite saturation from 98% to 585% were obtained by manipulating the calcium concentration. The results
show a nonlinear increase in calcification rate as a function of aragonite saturation level. Calcification increases nearly 3-fold
when aragonite saturation increases from 98% to 390%, i.e., close to the typical present saturation state of tropical seawater.
There is no further increase of calcification at saturation values above this threshold. Preliminary data suggest that another
coral species, Acropora sp., displays a similar behaviour. ...

Our results demonstrate that manipulating calcium
carbonate saturation through changes in calcium con-
centration has a highly significant short-term effect
on coral calcification. The work of Marubini and
Atkinson Žpers. comm.. and Langdon et al. Žpers.
comm.., which address similar issues by manipula-
tion of carbonate concentration in natural seawater,
arrived at essentially the same overall conclusion.
For the experiments described here, the rate of calci-
fication appears to increase exponentially as a func-
tion of increasing aragonite saturation state above the
100% saturation level, and reaches a plateau at satu-
ration values greater than 300%.

 

[Young Frankenstein]

robert do you have a link ? i want to follow up on this !!! Thanks for posting.

 

[robert]

The PDF is here" http://www.co2.ulg.ac.be/pub/gattuso_et_al_1998a.pdf

 

[Young Frankenstein]

The PDF is here" http://www.co2.ulg.ac.be/pub/gattuso_et_al_1998a.pdf

Thank you robert !!!!!!! I have to allot of reding

 

[Reef Pets]

Seems like an interesting topic. too bad there was no conclusion of if the topic is true or false. Just a wild guess.... I think Young Frankenstein is more than interested in the topic.

 

[Young Frankenstein]

I truly am, it will take a while for me to come up with some kind of understanding, and measurements but what is more interesting to me is you can have people keep the same parameters, one using 2 part and one using a reactor, the reactors some how work better as far as growth, in general. So there is more to it than low phosphates CA and MG.