Help with Brackish Aquarium

[FiremouthManAl]

Hi I wanted to start a low level Brackish Aquarium for a figure eight puffer, and wanted to put established media in the tank however im worried the salt would kill the bacteria, would it be safe to start the puffer at fw and change the salinity slightly over the course of a couple weeks? I know people keep them in freshwater for a couple years but I want the best for the puffer.

 

[Delapool]

I believe the bacteria do need to adapt or change over to a different type but that's only from trying to remember a thread a year back (never done it). Have you tried a forum search or someone may know.