Zeovit ZeoBak The essential microorganism solution for a healthy, well-balanced and efficient bacterial fauna in a tank. ZEObak contains several bacterial strains, used in combination with ZEOfood and ZEOstart building up bacteria plankton. That is absorbed by many corals. Contains several bacterial strains that form a chain to reduce unwanted substances. 1. Dose directly into the tank. 2. If possible please switch off the skimmer briefly. 3. Dose 1 drop per 25 gallons/100 L once or twice a week, depending on tank stocking.