Here's my thoughts: I like the islands on the left and right but centre island looks out of place. Possible to join the 2 rocks that make your centre island side by side and bridge the two other islands with an arch? This would give a more open appearence and leave lots of room on the sand bed for corals such as brains and other bottom loving types. As I don't see anything on your sand bed right now this may not be at all what you want it's just what I like.
