I see you have no lighting, not much can grow on that . if you add a light leave it on 12 hours a day nothing will stay clean.also if you add a light dont use 12 hours a day start with 3 or 4 and work your way up to keep from getting a bad algea bloom.all things in the ocean need sun light. well on a reef that is.
well bigger is better. helps keep tank clean.But freaks on everything from sticking my hand in to adding new coral,and to many micro bubbles. Im making a refuge as we speak and will put skimmer in there to take care of bubbles. besides that does a great job collecting waste.