Lava rock is full of nook and crannies which make it ideal for planting or just to keep your fish interested in their enviromentr another natural product that has unique colouring making it a excellent focal point in the aqaurium suitable for both freshwater and marine setupsr please rinse gently with cold water before use to remove any dust or particles no need for chemical cleaning or use of abrasive sponges to cleanr aquarium enviroment should always be stabilised before introducing fish