DIY calcium/carbonate mix, where to get in calgary??

[kwirky]

I'm looking for information on mixing up my own calcium/carbonate dosing mix. The carbonate is easy with simple baking soda, but I've read that the calcium mix needs homework done to make sure you're buying something that doesn't have strange chemicals in it. Anyone in calgary who's already done their research and can enlighten me on where to get the stuff?

I'm wanting to get away from dosing kalk, which is such a pain, and just dose chemicals daily. Any help would be great.