I am a new fish person and I have decided to set up my 20 gallon fishless freshwater cycled tank to a lightly brackish tank to accomodate Figure 8 puffer fish. I have read up on the Figure 8 Puffer fish and it seems that he will survive better in a slightly brackish tank then a freshwater tank. All of the water and sand are new. So I would like to know what is the easiest way to do this. Additionally what kind of salt is the best to use ie: Aquarium salt or Marine salt. And what kind of small algae eater does well in a brackish fish tank.