Your Aglaonema will become as large as you want it to depending on the conditions you provide. If you prefer to keep it small and about the size it is now, then regular pruning is required. If you want it to grow much larger, then you will have to provide optimum indirect sunlight and warm temps. Repot one size at a time but only as it becomes very potbound. Light is the key to determinant of growth, not pot size or fertilizer.
