Simulating nature for brackish tanks

[songchi]

If brackish waters salinity in nature changes according to rise and fall of water supply, and ebb and flow of tides...is it better for tank to be constant or to simulate nature in it's higher and lower salinity?

[RTR]

Our captive fish cannot select their density by swimming into another area as they do/can in the wild, so to me keping the watersomewhat stable is more important. But in BW exacting accuracy is not major, small variations are relatively trivial.