I agree with Mojoe about the Iodine, although I do dose Iodine, I have a seasoned tank with almost all soft coral and the tank demands it. Your tank is too new. I have used Instant Ocean for 25 years, it is a good salt mix. Some others may deliver a bit more Cal and Mag but over-all they are all in the relative ball park. Your tank still has about 4-5 months left to get through the "complete" cycle. I would not start to load it now. Take your time and do your weekly parameter checks and get a feel for keeping the parameters stable. In my opinion, stability is what is overlooked most often in this hobby. Many, for example, will check say Alk and it is 12 DKH so they forget about it for a time and check it in 2-3 weeks and find it is 7-8 DKH and so they dose to get it back to 12 DKH...not good. You don't want wide swings in any parameter. After the tank goes through all the mini-cycles and algae out breaks, then you can add some coral. Also, remember that at the 6-8 month mark your lights may need to be changed (depending on what lighting you have).