Unsealed stone and concrete surfaces may also be destroyed by dissolved Epsom salt splashed or dripped outside the tank, due to the dried salt recrystallizing and opening up cracks and fissures. Epsom salt just isn't corrosive in the way sodium chloride (desk salt) is but chlorine can assault some surfaces https://thesocialroi.com/story8403562/a-review-of-how-to-isolate-tanks