sodium bicarbonate (baking soda) vs sodium carbonate (soda ash)

[ScubaSteve]

Originally Posted by don.ald

good question. also, i was thinking of going to the pharmacy and purchasing chem grade sodium bicarb. vs food grade (baking soda).
wondering if there is a difference/ (sorry didnt want to hijack the thread)

Food grade should be sufficient. I used pharm grade for a while and even ran it through my HPLC at work and found that food grade was just as pure (as long as it was the unscented type. No need to pay the premium.