brackish to marine tank

Question
I have a 30 gallon tank right now, and it is a brackish tank. I have it cycled and I wanted to stock it with baby Columbian sharks (between 3 and 5 of them, starting around 2 inches long each, no other fish in the tank except an algae eater maybe). I realize they grow quickly and realize they will need a full marine set up in a year or a year and a half (and a bigger tank). I am a little confused on setting up a marine tank, is live rock necessary? Do you know what things I can carry over from the brackish to the marine tank? I also don't know if I should be slowly changing my brackish tank to the marine over the course of the year, or just increase the salt levels and make no other changes until they are in their new tank.
Thanks so much (hope you can answer this)

Answer
Hello Rachele,

I am not familiar with brackish tanks and really cant offer too much for you with regards to changing it over.

BUT, if you have no fish or anything in there when you make the change, it shouldnt be too bad...

You dont need live rock for a saltwater tank, although that rock is designed/used for biological filtration... without live rock, you will have to do more maintenance, i.e. water changes, and cleaning, that would be normally done naturally...

Good luck in finding out more informaiton you need that i am unable to provide.

good luck

bill