Yes and no. Like everything in the hobby it depends upon your tanks goals. Some people say that certain soft corals and some branching LPS prefer water that is a little murky. Examples that I know of: zoa, goniopora, hammer, frog spawn, Elegance, star type polyps, and xenias. These corals seem to thrive in water rich in nutrient. SPS seem to prefer sparkly clean water and fish won't mind either.