I'm cleaning and doing up my 20g salt tank tomorrow with some new Live rock and I just want to know If I can use The large (Really large) bottles of mineral water that you find in a store or should I just stick with tapwater?
Never use mineral water in aquaria. Most sources of mineral water contains salt. The salt is sodium bicarbonate not sodium chloride. Mineral water also contains sulfur compounds. Bubbly mineral water also contains a big dose of CO2 which your tank does not need.