Kalkwasser
 

Found another source for kalk, its not hugely cheaper, but here are the details. Its from a chemical company that my mom orders from to get the chemicals for her lab, there site is http://www.sigma.com and you can order it to your house, you dont have to be part of a lab or anything the cheapest one is $88.20/5kg ($17.64/kg) as apposed to JL @ 24.95 . Not a huge saving....but better then nothing..Although i might be inclined just to get it from JL

Calcium carbonate (CaCO3) £4%
Chloride (Cl) £200 mg/kg
Sulfate (SO4) £500 mg/kg
Cd <50 mg/kg
Co <50 mg/kg
Cu <50 mg/kg
Fe <500 mg/kg
K <200 mg/kg
Na <100 mg/kg
Ni <50 mg/kg
Pb <50 mg/kg
Zn <50 mg/kg

Hi Sean, can you provide a complete URL to the product? I did a few searches over at that site and all I get is "No Products were found for your search."

thanks!

here yah go: http://www.sigmaaldrich.com/cgi-bin/..._CatalogSearch

the cheapest one is the 3rd last i believe.

hmmmm clicking on that link gives the same results, i just put CALCIUM HYDROXIDE into the serch box and hit go....