Rock first. Then sand. Then water (that has already been mixed, or that you bought at petco for $2 a gallon if you in a hurry).
1. You want your rock regardless of live, dead, ceramic, ext to be touching the bottom of your tank. You can dig it in later, but it causes the tank to be cloudy with sand again.
2. Only fill with water till you reach the overflow. If you stop before you hit the overflow the sand can settle and then you can add the rest in 24 hours. This will greatly decrease the amount of sand that ends up in your sump or integrated filter area. Also a good idea to clean your filter pad of sand after 7 days, then let it stay dirty till after tank is cycled.
3. If you can only mix 5-10 gallons at a time feel free to cycle your tank with Petco imagitarium water. Or spend a few days filling your tank. But don't mix the salt mix in the tank. If you have live sand or rock it will kill pretty much everything that was live about it. Nothing good ever comes of taking shortcuts in this hobby.
