Carib Sea ACS00797 Arag Alive Hawaiian Reef for Aquarium, 20 Pound, BlackBring the world's most exotic reefs into your home with Carib Sea's Arag Alive substrates. Helps maintain a proper pH for the life of your aquarium without the constant addition of chemicals, and creates a biological balance to discourage nuisance algae. Caribe Agar Alive Hawaiian Black 20lbs It is developed from Caribe's cooperation with public aquariums and zoological parks, where authenticity is a must Made by Caribe Sea