Microbe-Lift PL creates a healthy pond environment by reducing ammonia and nitrogen levels, improving dissolved oxygen levels, reducing the build-up of waste from fish and decaying plants, and reduces odors. May be used when water is above or below 55°. Add to jump-start your biological filter. Safe for fish and plants. The beneficial bacteria contained in Microbe-Lift PL also seeds biological filters and even breaks down dead algae. 1 qt bottle will treat a 1,000-gallon pond for 4 months.