I emailed AquaticEco about their product and received this response:
Thank you for checking with Aquatic Eco-Systems. Here is the breakdown on CCB1, the beaded product which we carry at present:
Anhydrous
CaCl2 94%
Arsenic as As <3mg/kg
Flouride < 40 ppm
Heavy Metals < 20 ppm
Lead < 5mg/kg
Magnesium and Alkalai salts < 5%
Would this be a safe alternative to Dow flake? How much of this would be required in the formula to replace the dow flake?