1 gallon reef tank

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

I'd start with about 1/2 cup or less and test. 1/2 cup should put you in the neighborhood of 1.023.

I've got a 1g tank on my desk and it's pretty cool. It's got about two pounds of live rock, shallow sand bed, and small power filter. I just keep a few blue leg hermits in there though....too small for fish. Oh, I've got some aiptasia in there too

I have to top it off daily....it takes about one turkey baster full of water. Then I do a 25%-30% every week. Levels are fine and all is going well.

put some zoo's in there gcvt

what could you keep in a 1 gallon tank? do they make some a little bigger? like 3 gallons or so?

yes they make all different types and sizes.

http://www.nano-reef.com/