Agricultural lime good for dosing Calc & Mag?

[Markushka]

I was at walmart today and saw a bag of agricultural lime, its main ingredients were CaCO3 (calcium carbonate), MgCO3 (magnesium carbonate) and may have also had CaO, MgO, CaOH2, MgOH2, Mg, Ca. would this be a good substitute for calcium and magnesium additives to my reef tank? I'll try and get exact percentages and contents. I know I can use pickling lime, but I haven't found it yet, would this work well too? Anyone ever try this? Thanks in advance.

[Amphiprion1]

It's not really fit for use. The purity is much lower than acceptable and the vast majority of the ingredients are downright insoluble--may even cause precipitation. I would stick to pickling lime, which is strictly CaOH2, with some minor impurities that tend to precipitate anyway (minus strontium, but there is very little).