When Mixing Aquarium Salt, it is best practice to use RO/DI water. Fill a clean 5 gallon mixing container with desired amount of Saltwater to be prepared. Slowly add aquarium salt into the RO/DI to avoid a sharp increase in temperature, and an over saturation of Salt. This helps to prevent precipitation of Calcium, Alkalinity and other trace elements. Using a hydrometer (included in our starter kit), bring the salinity between 30-33 PPT . Please allow 2 hours before doing a water change. If water does not mix clear please contact us for further mixing tips before doing a water change.