Penac W helps to improve the substrate environment. Sprinkle the Penac W powder at the very bottom of the substrate layer. Highly recommended as an additive towards improving aquarium ecosystem health.
Primarily, it prevents the substrate from becoming anaerobic and improves the substrate environment (when applied at the bottom of the substrate upon setup). It also can be added directly to aquarium water in case of an oxygen shortage (such as in the case of co2 overdose), causing rapid oxygenation of the water.
Apply 3 Spoonfuls (included with Penac W) to the bottom of the Aquarium when setting up new substrate in a 60cm (24 inch) aquarium (such as 60-P, 60-F, etc).