Winter fish Pond Care beneficial bacteria. Just one easy treatment every other week and your fish pond and koi fish will be in perfect condition in the spring!Removes deadly Ionized Ammonia and toxic Un-Ionized Ammonia from your winter pond water Removes toxic nitrites and nitrates. Works in very cold water (as low as 35- degrees F). Beneficial bacteria reduces and digests bottom sludge all winter. Helps maintain a healthy immune system. Arctic Blend will not deplete the oxygen level in your pond water. Beneficial Bacteria reduces spring clean up. 100% natural, NO CHEMICALS, safe for pets and wildlife. Some of the microbes that make up “Arctic Blend” are harvested from the frigid waters of the Arctic ocean. These unique microbes make their own natural anti-freeze and thus perform at their peak in pond water temperatures between 35 and 52 degrees F. You can start using Arctic Blend’s beneficial bacteria in the fall and it’s made for treating your winter pond water all winter. If you have any left over in the spring, you can use it until your pond temperature reaches 65 degrees F. ARCTIC BLEND is the ONLY winter pond care product on the market that can remove ammonia, nitrites, nitrates, phosphorus and digest sludge in winter conditions with water temperatures less than 39 degrees F.