Buying Bulk Calcium

[Scrubber_steve]

Dowflake (Calcium chloride dehydrate) is 77-80% calcium chloride “Type S; Grade 1, Class A.”
Looking at chemical suppliers data typical grades available are -
reagent grade
food grade
molecular biology grade
extra pure, Ph Eur, USP, BP

where does Dowflake fit into these catagories, and, what is the lowest grade that is fine for aquarium use?

 

[Randy Holmes-Farley Verified Community Expert]

Dowflake isn't graded by any of those grades.

All of those grades are likely OK.

I determined Dowflake was OK (actually identical to some hobby brands) years ago by testing it:

Aquarium Chemistry: Purity Of Calcium Chloride
https://www.advancedaquarist.com/2004/3/chemistry

 

[Scrubber_steve]

Dowflake isn't graded by any of those grades.

Thanks for the link Randy.

I got the grade for Dowflake from this
http://www.usmix.com/download.php?7e0d11fa93518a23d958088e42f548d9