Hi. I'm looking at putting some corals in my tank. It's my first attempt at corals and there are so many to choose from. I have a 60g tank and only want a few corals, but if I'm honest I struggling to see the difference between soft and hard. I like the look of brain corals and mushroom corals but would like some that will flow with the water. The ranks is a few months old so I'm in no hurry but how long would you suggest I wait before adding them. Thanks