The Pond Digger Cold Temp Beneficial BacteriaThe Pond Digger COLD WATER TEMPERATURE Dry Bacteria has been scientifically blended and tested to produce maximum sludge eating and organic reducing results in ponds, lakes, streams, hybrid Koi ponds and water gardens. Our personal water treatment line will support clear water, healthy fish and pristine water quality. This is the bacteria blend that we recommend for weekly maintenance on waterscapes with water temperatures ranging from 40 60 degrees.