The only difference from fresh and brackish is that you add marine salt. You can use the same filters, lighting, substrate and media for fresh/brackish. Though for brackish you want a higher ph 7.8-8.3 which for me is easily achieved by using aragonite sand which dissolves in acidic water and raises the ph. Cycling the tank is the same as fresh. Add the substrate, decor, water and filter and let it run for 4-6 weeks without fish. Add a food source for bacteria to start colonizing, a 1 inch piece of shrimp works, just put it on the bottom and let it rot away. As it rots and raises ammonia levels, bacteria will form to turn that into nitrite and bacteria will then form to turn that into nitrate. Once levels of ammonia and nitrite hit 0 you can add fish.
