Like anything, you need to take it slow and find out what will be "easy starters" at your lfs or here. there are corals that are hardy that you can start right now and they will do fine. tany was started about 2 months ago...once cycled I have added no more than a fish and a coral or 2 every 10 days or so. I have a 90 gallon also and perfect parameters still. You just have to make sure you add and keep your calcium constant. I use reef complete because it has iodine and stronium in it also plus the calcium. My first purchase was a small zenia...very fun because they pulse like little hands. They don't like strong current, just mild I have found. Now I have a cabbage leather, a colt coral a small frag of zoos and 2 kinds of mushrooms, all thriving excellent. I also now have a pair of maroon clowns and just a couple of days ago put in a 6 line wrasse which I love too. Very fun and colorful. we have also had fun because we just got a cleaner shrimp and do have a few crabs that are neat, emeralds. The cleaner shrimp is very cool he jumps in the water like superman off rocks when I put phytoplankton in. oh yeah with 6 line wrasse we also put small red starfish...not a linkia, they are very sensitive. These are very cool...they take barely any bioload and my daughter named it strawberry!! Too fun..good luck!! My next purchase probably another coral....some polyps probably, a royal gramma and then wait a couple of weeks and then my last fish...a blue tang. ....:happyfish
