Have you started on cycling the tank?
Salinity is good, don’t worry too much about ph right now. If you started with all dry rock, feel free to throw a piece of raw shrimp in there or pure ammonia (no additives or surfactant) to 2ppm. After a week or so, nitrites will rise then nitrates. Once you see no more ammonia or nitrite registering on your test kit, dose ammonia to 2ppm again. If ammonia is consumed within 24 hrs, and you don’t see nitrites registering either, your tank will be cycled. Takes a few weeks. You can add one of the bottled bacteria’s (Dr. Tim’s One & Only, Microbacter 7, Fritz turbo Start, Biospira etc) to speed up the cycle. Same thing, add ammonia to 2ppm or ammonia source and bacteria and wait. Keep lights off also. Once your cycles, do a good water change to get nitrates down and your good to go to slowly add a fish.