All ponds rely on biological waste breakdown cycles to keep them healthy.Bio-Start helps to rapidly establish this important natural process and so reduces new pond syndrome.Can be added directly to pond or filter.Use also to help \'kick start\' biological process in the spring and also boost filtration when new livestock is added.There are 8500million bacteria per sachet.Always read manufacturers instructions carefully and follow guidelines fully.One pack treats 2000 gallons / 9000 litres