Autumn/Winter Prep is specially formulated for pond winterization. Microbe Lift Autumn/Winter Prep is a 2-part program engineered to provide an effective method of winter pond maintenance. Autumn/Winter Prep is: Environmentally Friendly Will continue to provide sustained biological activity even in water temperature under 55° Helps to jump start your pond to a healthier environment in the spring Helps to maintain a healthy immune system for your fish during the winter months Reduces buildup of dead leaves and organic sediment all winter long If frozen, the bacteria will remain effective after thawing out Effective in darker conditions (under ice and snow) Safe for fish and plants. Available in 2 sizes. Quart size contains 32oz liquid and 2 water soluble enzyme packets, Gallon contains 128oz liquid and 8 water soluble enzyme packets. For best results, use 4 applications, one month apart. Start your winter maintenance program in early fall. This will give the bacteria and cellulase enzyme sufficient time to acclimate themselves before the winter freeze. After completing the Autumn/Winter Prep, you can resume use of Microbe Lift PL and/or use Microbe Lift Spring/Summer formula.