Hopefully, you have done the research ahead of time and determined which Sea Salt is best for your particular aquarium.
Once the system has been checked for leaks, shut the system down and remove a few gallons of water from the tank and sump.
If you are using "Live Sand", open the bag(s) and pour it into the tank. The water will become cloudy, but it should clear up once you have turned on your filtration system.
If you are using non-live sand, rinse it in freshwater to remove the smaller particles, then pour it into the tank.
Next, add your sea salts. If you are using a sump, pour the sea salts into the sump and turn on the sump return pump. This will circulate water over the sea salts and help them to dissolve more quickly. If you don't have a sump, turn on any powerheads in the tank, along with your filter. As the sea salts dissolve, keep adding more and test the salinity frequently until the desired level is reached.
Next we are going to Install the Live Rock & Run the System