Tums, eggshells, ground limestone are the same active ingredient Calcium Carbonate. This salt is only slightly water soluble, but reacts with acids to break down. The "quick" fixes like Rot Stop are The soluble salt Calcium Chloride. Hydrated lime (Calcium Hydroxide) is also quick acting but caustic. In most instances BER appears early on immature plants and cease as plants mature. The quick fixes get a lot of credit for what the plant was going to do anyway.
