Purity of Kalkwasser

[robitreef]

I was looking up some info on Kalkwasser and came across Warner Marine Research's website.

They claim their Calcium Oxide is better then Calcium Hydroxide (Kalkwasser).

This is an excerpt from their website:

Warner Marine Research Kalkwasser Plus is the only Calcium Oxide product available today. It is produced entirely from Pharmaceutical Grade (U.S.P.) Calcium Oxide, the highest quality raw material in the hobby. Inferior competing Kalkwasser products are produced using poor quality ââ"šÂ¬Ã…"œfood gradeââ"šÂ¬Ã‚ (FCC) or industrial grade Calcium Hydroxide, Food Grade Calcium Hydroxide contains up to 30X the heavy metal concentration, including Lead compared to Analytical Reagent Grade Calcium Oxide.

So, has anyone challanged this assertion, or done any testing?
Could it be true info, or just a marketing ploy?

 

[Randy Holmes-Farley]

I am not aware of any testing. I use a food grade calcium oxide from the Mississippi Lime Company (which can only be bought in bulk, like a club group buy).

I discuss lime grades in this article:

What Your Grandmother Never Told You About Lime
http://reefkeeping.com/issues/2005-01/rhf/index.htm