BROMINEBromine is a minor element with an average seawater concentration of 65 ppm. It is an essential element for all inhabitants in your aquarium and plays a vital role in the synthesis of chromoprotein and zooxanthellae. Corals use bromine for the synthesis of photosynthetic enzymes. Bromine can quickly become depleted in your aquarium, so maintaining seawater levels is important. Directions:This product is to be used in conjunction with calibrated testing equipment or ICP-OES to determine depletion.2 drops (0.1ml) will raise 100L of aquarium water by 0.06 ppm. Ingredients:Concentrated Bromine60,000ppm CAUTIONKeep out of reach of children and pets. Not for human consumption. For marine aquarium use only. StorageKeep out of direct sunlight.Always secure cap on.