Accelerates the development of the biological filter and helps clean a dirty aquarium. Rebuilds bacterial flora after medical treatment. How does it work? Contains over 345 million live bacteria per teaspoonful. Breaks down organic compounds that cause dangerous conditions such as ammonia and nitrite poisoning and low oxygen levels. No refrigeration necessary. Directions Use when setting up an aquarium and every week ongoing. Continuous use assures an active biological filter, cleaner aquarium, healthier fish and good water quality. For use in fresh and saltwater.