William Tricker Inc. Aqua Meds Arctic Blend Beneficial Winter Pond Bacteria 32 Ounce Arctic Blend is a winter pond care product that can remove ammonia, nitrites, nitrates, phosphorus and digest sludge in winter conditions with water temperatures less than 39 degrees F. 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 100% natural, NO CHEMICALS, safe for pets and wildlife