Salinity Level

Depends on the fish. Diffrent fish live at diffrent levels. Most can be adapted fairly well up/down the scale a few points. But it really depends on the fish.
 
^^^ Agreed. My puffers need an SG of 1.005-1.008..... Full-on marine is around 1.020-1.025..... Mid-Brackish is 1.010-1.015... high-end is 1.016-1.019
 
AquariaCentral.com