When the rock is clean, and that does not mean that you remove everything from the rock, just the unwanted algae, sponge and other life forms that may be dying, rinse it again in the second bucket. Now put it on the tarp or piece of water resistant material again, or add it to the aquarium. As you continue to do so you will eventually have cleaned all the rock which will then be ready to be added to the aquarium. Before adding the rock though, you will need to add the sand. Normally, if you just pour the live sand out of the bags it came in, it will cloud the tank a great deal.
Sand contains very small particles besides the grains.
When these small particles mix with the water, the latter will cloud. Avoid this by being really careful in how you add the live sand to the tank. Close the top of the bag, or hold it closed with you hands, so no water can get into the bag and no sand can get out. Lower the bag into the aquarium all the way to the bottom. When the bag is at the bottom, tilt it sideways and open the top.