Aquatic Rainbow Aquarium Pebbles 4.4lb are made of non-toxic material, safe to your fish and will not affect PH of the water. Colorful gravel pebbles can be used as decoration for fish tanks, Aquariums, Vivariums, plants, vases or other places 4.4 Pounds. ,Aquarium gravel is the ideal way to enhance the appearance of your aquarium. Chosen from selected silicate aggregates known for their inert properties. Suitable for all types of aquarium set-ups including coldwater, tropical and saltwater. .is also the perfect planting medium due to its finer quality. In