OK we went back to the lowers spread out version, of course i didn't get it exactly the same despite my efforts. My students also ran out of patience with me when I couldn't get it symmetrical. One explained that its ok if its higher on one side as opposed to in the middle nature isn't always symmetrical. They had a laugh at my expense and we remembered its their tank so if they are happy we are all happy. The small piece in the front is a piece of live rock we are using to boost the cycle. We will likely remove it, although one student proposed we leave it and built an island of whatever we decide as a class is our favorite coral?