This formula of beneficial bacteria and barley helps to jump start your system in the spring or in the fall after any large clean ups. It is designed to accelerate the decomposition of leaves, twigs, muck and other organics during the fall and winter months. This specialize bacteria will start working in cold water (0oC to 15oC)when more traditional bacteria is still dormant. Spring & Fall Prep is packaged in easy to use pre-portioned water soluble packets and safe for fish, plants, birds and domestic animals. 1 packet/ 1,000 gallons.