78-82 degrees is ideal. As for salinity, remember that different regions of the world where marine life lives, salinity values differ. For example, the salinity of the Red Sea is different from that of the Caribbean. Reef Flats have a different salinity than reef slopes. Areas where rivers run off into the oceans also have different salinity values than open oceans or other areas further away from estuaries.
This is due to the amount of evaporation or precipitation in those areas.
Long story short, life evolves and adapts. The same can be said about the living animals in our tanks. Their really isn’t just one salinity or temperature value that is ideal. What may be good for one aquarist might not be optimal for another. Moreover, animals given small fluctuations over time will adjust and acclimatize to the different water parameters.
The same holds true with certain corals and their ability to dispel one strain of zooxanthellae for another that best suits the corals needs given the environment at that time.
Hope this helps...