Keep your filter running to its full potential by maintaining it correctly. Bermuda Filter Activator helps establish new biological filters & maintains efficiency for existing filters. Designed to provide the optimum condition for biological filters to perform to their maximum potential, it provides essential salts & nutrients which are required to encourage the growth of healthy bacteria within your pond. 1 litre will treat ponds up to 42, 460 litres/ 10, 000 gallons.