On occasion, our corals grow too large for the aquarium in which they reside. They either grow upward and out of the water (only slightly of course) or they grow right into the glass and shade anything below. In either situation, the corals need to be trimmed, otherwise the overgrowth can have serious negative impacts on other inhabitants. For corals growing upward, they will stop at or just below the water’s surface, harming virtually nothing in the process unless they start plating outward from that point…which is unlikely, especially under really intense lighting. For corals that outward instead of upward, there is a good possibility that neighboring corals could be left in the shadows, not receiving enough light to survive. If shading isn’t an immediate threat, then other forms of coral warfare might be. Corals will sting neighboring corals, causing massive tissue lost and bleaching for the loser of that turf war. In any situation where coral growth is too excessive, simply fragging the corals is the best and easiest solution.