Is CaCl2 always CaCl2??

[wildwest450]

Is there a difference in this stuff? The last batch I used was in small bb like form, this is flaked, will it kill me?

Just want to double check before ordering, being all non scientific and what not.

http://cgi.ebay.com/Calcium-Chlorid...I&otn=21&pmod=200539197438&ps=54#ht_500wt_922


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[dwarven_stout]

It's just like the difference between kosher salt and sea salt.

 

[ajdelange]

Yes, there are differences. There is anhydrous, monohydrate, dihydrate, tetrahydrate and hexahydrate. I suppose any of these can be had in flake, prill, or powder form. I had always assumed that it was the dihydrate which is commonly sold in LHBS's because that is the most stable with respect to water pickup from the air but I then noted that calcium ion concentrations in solutions made with the prilled stuff from the LHBS were different from the ACS grade stuff labeled as the dihydrate I use in the lab. The LHBS stuff did not yield enough extra calcium to convince me it's the anhydrous form so at this point I'm a little mystified. I now assume it is the monohydrate when I do addition calculations. Further investigation revels that there is some calcium hydroxide in most of the "calcium chloride" sold. I guess the bottom line is that unless you are buying assayed stuff or ACS grade you don't really know what you have.

100 mg/L of the anhydrous gives 31.56 mg/L calcium and 100 mg of the dihydrate 27.76 mg/L so as long as your uncertainty is in the anhydrous - dihydrate range it doesn't make that much difference. But 100 mg/L of the hexahydrate only gives 18.79 mg/L. That is a big difference wrt to the anhydrous.

 

[dwarven_stout]

Interesting. Guess I learned something.. I always just assumed everything was the dihydrate form as well, but I never actually checked it.

 

[DeafSmith]

Is there a difference in this stuff? The last batch I used was in small bb like form, this is flaked, will it kill me?

Just want to double check before ordering, being all non scientific and what not.

http://cgi.ebay.com/Calcium-Chlorid...I&otn=21&pmod=200539197438&ps=54#ht_500wt_922


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The list of applications provided, the low price (relative to LHBS), and the "industrial grade" would worry me. I know they claim 99% pure, but what is that other 1 % ?

 

[dwarven_stout]

the low price (relative to LHBS)

Gotta say, that's one thing that never worries me. LHBS prices tend towards the ridiculous. I support them, but only because I want to have that emergency yeast packet sooner than 2 priority mail days.

 

[wildwest450]

Once again, reading Aj's post is like trying to decipher Mandarin Chinese, but I appreciate the technical breakdown.

I guess i'll trust that an online hbs has the "correct" type and just buy it from them. I'll consider it stupid tax.



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[ajdelange]

Oops. Guess I need to tone down the geekiness level some.

In a nutshell, some forms of calcium chloride contain more water (and thus less calcium and chloride per unit weight) than others. In calculating how much to add for a particular calcium level, for example, one has to consider this. The spreadsheet designers must either pick one form or give you the option of telling the spreadsheet which form you have. But that's difficult to determine unless the product is clearly labeled and the stuff from the LHBS isn't.

Perhaps more important is that one should use only food grade calcium chloride. If you bought it from the LHBS it should be. If you bought it from e-bay unless it is labeled food grate (FCC) it may have been produced for deicing driveways.

 

[wildwest450]

Oops. Guess I need to tone down the geekiness level some.

In a nutshell, some forms of calcium chloride contain more water (and thus less calcium and chloride per unit weight) than others. In calculating how much to add for a particular calcium level, for example, one has to consider this. The spreadsheet designers must either pick one form or give you the option of telling the spreadsheet which form you have. But that's difficult to determine unless the product is clearly labeled and the stuff from the LHBS isn't.

Perhaps more important is that one should use only food grade calcium chloride. If you bought it from the LHBS it should be. If you bought it from e-bay unless it is labeled food grate (FCC) it may have been produced for deicing driveways.

Much better, thanks! I did notice several other sellers advertising "food grade" that was safe for aquarium use and cheese making, sounds better. I still think i'll just bite it and order from a HBS.


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[RCCOLA]

I found CaCl2 at the local sprawlmart in the canning section. They call it "Pickle crisp"

Also, CaOH2 (pickling lime) was right next to it.

 

[Misplaced_Canuck]

Much better, thanks! I did notice several other sellers advertising "food grade" that was safe for aquarium use and cheese making, sounds better. I still think i'll just bite it and order from a HBS.


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... Midwest has it for cheaper than ebay, FYI...

M_C