The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.
Brackish fish do best in water with a salinity of 1.010 - 1.015 and a pH of around 7.5 to 8.4. It varies with the type of fish you want as well, a bit. Using a natural sea salt mix will will bring your pH and salinity levels up to where you want them. You will want to add your salt slowly, until your hydrometer reads around the SG mentioned.
Also, bumblebee gobies don't necessarily NEED brackish water, I've got a couple in a FW planted tank, pH ~ 7.0 with no salt!
Regarding pH, it's pretty commonly advised that the pH remain fairly constant, which is more important than the actual level (unless you are keeping very finicky fish!)