Food Grade VS Agricultural Grade

[Myka]

I am ordering some fertilizers for my planted freshwater aquarium from www.aquariumfertilizer.com (http://www.aquariumfertilizer.com) and I notice they have Calcium chloride for US$2.50/lb. With our dollar so strong, that is less than $3/lb, plus I can order another 2 lbs of ferts on my order and not have any increase in shipping, so why not? Good price. However it is agricultural grade, not food grade. I asked the vendor how pure it is, but she couldn't give me an actual number although she said "naturally occuring impurities". Well, Hydrochloric acid is naturally occuring too. ;) I have always used food grade, so I am a bit concerned. Has anyone used agricultural grade? Does anyone know the actual numbers of purity? Should I be concerned at all?

[rayjay]

I have been buying Dowflake and sometimes General's calcium chloride for many years and it's technical grade, the same grade as the calcium hydroxide that I've been using for many more years in my tanks as limewater for replacing evaporated water.
I have never seen agricultural grade chemicals so perhaps they mean technical grade.
The technical grade calcium hydroxide I purchase comes from the farm co-op that sells it to farmers to use as a disinfectant on the barn floors.

[StirCrazy]

agacultural grade is below techinical grade. with out a complete content listing I would be hesident to use it.

Steve

[Myka]

Ok, thanks Steve.

Thanks for the post Rayjay, but upon hearing that agricultural is even lower grade than technical...just not worth the potential risk.