Estes Spectrastone Ocean Beach Pebble Premium Aquarium Gravel. Create a beautiful environment for your lil' swimmers with high-quality, natural Spectrastone Spectrastone Ocean Beach Pebble Premium Aquarium Gravel. Perfect for freshwater aquarium or terrariums, this durable, non-toxic gravel is pH-neutral and made in the USA. Your finned friends will be swimming in style with this so-fish-ticated gravel in their tank! Key Features: Made in the USA. Durable, long-lasting substrate for aquariums and terrariums. Non-toxic, pH-neutral gravel is safe for all your finned friends. Natural color. Rinse before use.