Looks great. Be on the lookout for adequate spacing on the sides of the rock and the back for when you do cleaning like scraping the glass or syphoning water. Nice job though
Off to a good start....I personally would do away with the arches (looks unnatural to me)....maybe have one arch going from island three to island two. I think I would also make the first island less of a tower (only because it will be hard to use that space with it standing straight up like it is. Just my opinion of course