Is Coral Snow Calcium carbonate or Calcium bentonite?

[Myka]

From another thread...

I've heard some people say that Coral Snow is likely Calcium bentonite. I'm not sure if that's true or not, but wouldn't that make more sense than Calcium carbonate?

It is carbonate, I've done simple analysis and posted in Reef Central some time ago. May be is good to start new thread here. Actually it is chalk, not pure calcium carbonate (there are some magnesium etc.) and it is about 400 grams in 1 liter RO water.
Way do you think bentonite is better than calcium carbonate? Bentonite is aluminosilicate just like zeolite and I don't really think it is good idea to spread fine particles containing aluminium in a reef tank.

I did not say bentonite would be better. I just said that I thought it would make more sense (to me). Zeolite types are more complex than I've had time or interest (so far) to understand very well, though I thought that some zeolites adsorbed aluminum, so my understanding was that adding assumed Calcium bentonite while using zeolites would be of no concern. I know little of bentonite, but reading about it's abilities seems to line up with Zeovit's claims of Coral Snow. So it made sense to me when a few someones told me it was bentonite. I never researched it further.

This is the thread you refer to I assume? http://www.reefcentral.com/forums/showthread.php?t=2509907

Interstingly, "reefvet" replies to your thread, with no actual data mind you (claiming it is clay, assuming he means bentonite), though I wonder if he did his own testing (he's a biologist).

Seeing as our tanks are full of Calcium carbonate, why would there be any benefit to adding very finely ground Calcium carbonate powder mixed with RO? What's the science behind that? Flocculation from attraction of positive charges?

 

[biom]

Yes, same thread, thank you.

Seeing as our tanks are full of Calcium carbonate, why would there be any benefit to adding very finely ground Calcium carbonate powder mixed with RO? What's the science behind that? Flocculation from attraction of positive charges?

Science? I don't really know. But practice proves it works if you have cloudy water, I'm using it after cleaning the glass or after siphoning detritus out. It helps a lot, the effect is similar to active carbon. Also i'm using when fraging corals - i'm not sure if it helps for faster encrusting, but it helps to reduce extra mucus that corals produce.

 

[robert]

I don't know what "coral snow" contains,,,however I would not be surprised...

I use this:

http://www.amazon.com/Yerba-Prima-B...102604&sr=8-2&keywords=bentonite+great+plains

I add 12-20 drops (400 g tank) into the intake of my return pump or you could shake it up in a bottle of tank water and add it directly.

It is highly charged (ionic) and will look like a clump of oil (except it sinks) and will take a good bit of shaking to disperse it into the water.

Its been used in freshwater for some time...I don't know of anyone else using it in a reef but I've been using it for several years and I found it works quite well, despite the conventional wisdom that the ionic content of saltwater should reduce its effectiveness. I guess thats why no one else uses it - but they're wrong as has been confirmed with experimental testing.

3.5. Effect of temperature and salinity

"The influence of salinity on phosphate adsorption by unmodified and modified clays was studied at 0, 20 and 35 psu salinities. These values simulate salinities in fresh, brackish and marine waters, respectively. The influence of temperature on phosphate adsorption was determined at temperatures ranging from 5 to 35 °C. As shown in Fig. 6, high temperature is advantageous for phosphate adsorption on bentonites. Fig. 6 shows an increase in the adsorption capacity with an increase in temperature. This indicates that the adsorption reaction is of endothermic nature and the ion-exchange mechanism is favored at higher temperatures. The increases in adsorption capacity of unmodified and modified clays at higher temperatures may be caused by the enlargement of pore size and/or activation of the adsorbent surface (Masue et al., 2007; Yan et al., 2010). Likewise, decreased adsorption capacity of unmodified and modified clays at lower temperatures, may be caused by decreased pore size. The fraction of phosphate removed at the extremes of the salinity range, illustrates that salinities close to those of marine water had the most prominent effect on phosphate ion removal, followed by brackish and fresh water. Hence the phosphate adsorption capacity followed the order: fresh water <brackish water<marine water (Fig. 7). The effect of salinity may originate from two physicochemical mechanisms. Firstly, ionic strength effects are expected to suppress ion uptake by the material. This is not observed in Fig. 7 however, where at higher salinities a relatively small, though well-resolvable, increase of phosphate uptake is observed. Secondly, osmotic pressure effects may favor uptake of ions from the aqueous phase on the material's surface. The data in Fig. 7 clearly disfavor an ionic strength effect, while they are in qualitative agreement with an osmotic pressure effect."

The whole artice can be downloaded from here:
http://www.researchgate.net/publica...l_waters_using_innovative_modified_bentonites

 

[biom]

Hah, we already have thread here at R2R https://www.reef2reef.com/threads/diy-kz-coral-snow-with-97-purity.211722/ Funny.

 

[robert]

Hah, we already have thread here at R2R https://www.reef2reef.com/threads/diy-kz-coral-snow-with-97-purity.211722/ Funny.

Sure...I have no idea whether coral snow is chalk or bentonite...just sharing an unexpected property of bentonite which might suggest a use in phosphate control along with its protein floculant properties...just thought some might like to see the study behind it...

 

[Eckolancer]

Following.

 

[biom]

Thank you for sharing this info, the only concern here in my opinion is not its limited effectiveness in salt water, but rather bentonite aluminium-silicate nature. Here is Randy's article about aluminium and its toxicity http://www.advancedaquarist.com/2003/7/chemistry

 

[Randy Holmes-Farley]

FWIW, I think that calcium carbonate has a net positive charge in seawater,

https://www.researchgate.net/public..._and_calcium_carbonate_in_artificial_seawater

so it will bind and potentially flocculate negatively charged organics and particulates.

It will also bind organics with carboxylic acid groups that bind strongly to the calcium, even if, perhaps, it had a net overall negative charge (say, at higher pH).

 

[biom]

Very good read, thank you Randy!

 

[robert]

Interesting:

This gets quite complicated...I guess you really have to check the sources closely to see what they're really telling you.
For example:

 

[Randy Holmes-Farley]

Yes, I see that paper is seeming to claim a negative value. It may all depend on exactly what is in the water and what binds to the surface (organic and inorganic).

 

[Myka]

Hah, we already have thread here at R2R https://www.reef2reef.com/threads/diy-kz-coral-snow-with-97-purity.211722/ Funny.

Hmm, yeah that's the only thread that came up when I searched "bentonite" on R2R. I didn't think it actually discussed any true analysis of Coral Snow.

 

[robert]

I've not used coral snow - but I would expect it would be obvious if it were bentonite based or calcium-carbonate based.
Bentonite has some very distinguishing characteristics. If I get some time I'll try and post up some pictures.

 

[robert]

I've looked at other threads online. Its reported that coral snow, when dried results in a white powder that readily dissolves in acetic acid - if so, its not bentonite.

 

[biom]

Hmm, yeah that's the only thread that came up when I searched "bentonite" on R2R. I didn't think it actually discussed any true analysis of Coral Snow.

No, it did not. Actually it is based on my poor analyses I'm afraid - if you click on "a calcite chalk" link in first post it will open the same RC thread .

I've looked at other threads online. Its reported that coral snow, when dried results in a white powder that readily dissolves in acetic acid - if so, its not bentonite.

Yes, it was me , from above mentioned post in RC: "...I've made few simple tests and I'm pretty sure that it is chalk - it vigorously dissolves in acetic acid without residue, and after dehydration it looks exactly like chalk..."
And KZ are not hiding what is in it anymore, from their site :"...Coral Snow contains among others a natural Calcium-Magnesium Carbonate mix... " http://www.korallen-zucht.de/en/Salt-Water-Aquarium-Care/Elements/Coral-Snow.html

 

[Randy Holmes-Farley]

Do you have any sense how it differs in size from products like Aragamight or Kent Liquid Reactor that are fine calcium carbonate particles? Aragamight claims to be 10 microns.

 

[s2nhle]

Great information.