Follow the directions on the salt mix check your s.g. prior to adding to your tank. I really do wish you luck with this but, a 1 gallon reef is going to be really hard to keep stable and you won't be able to put very much in it all! Also if you want corals or other light sensative critters you are really going to need to keep temp in mind. I don't know how much experience you have with s.w. looking at your tanks ," really nice btw
", they look like they are all fresh to me. Small volumes of salt water are very,very hard to keep stable. Your s.g. is going to fluctuate wildly if you odn't stay really on top of your water changes and topping off your tank. I really do wish you the best of luck but, would encourage you to start out with a larger tank at least 20 to 30 gallons.
hope this help and not trying to flame you
Chris