About this product range:~ Roman decorative aquarium gravel is the ideal way to enhance the appearance of your fish tank. Chosen from selected silicate aggregates known for their inert properties in a choice of natural stones or coated in a colourfast resin for trouble free fish keeping. Suitable for all types of aquarium set-ups including coldwater, tropical & saltwater. Roman decorative aquarium gravel is also the perfect planting medium due to its finer size. Increased surface area allows for enhanced anaerobic activity. Will not change the PH of the water.