Freshwater bacteria on Saltwater

[BCOrchidGuy]

I agree, the bacteria is different. I don't see any advantage to doing it this way other than when you add salt you'd kill off all your bacteria and you'd end up with your ammonia spike and your new bacteria would have something to consume. I doubt however that it would make much difference in your cycle time. Don't forget as well most of your equipment will likely need to be changed as well. For the most part salt water tanks need tons of water movement, if you want to grow coral you'll need higher quality lights with different colour spectrum than if you were keeping a fresh water fish tank, or a freshwater plant tank. Live rock etc, it's easier just to start fresh (new).

Doug