I would not get rid of your wet/dry. It's the best type of filtration for a saltwater tank, because it provides a nice amount of aeration to the tank (as does a protein skimmer). A lot of people fill their tank with a 1.5 lb of live rock per gallon and just throw a few powerheads in the tank for filtration, but personally, I don't think this is enough. It doesn’t provide the aeration that a wet/dry does. If you really want to get rid of your bio balls though, I would wait until you have about 75 or 80 lbs. of live rock.