Microbe-lift Bio Black is specially formulated for ponds lakes and lagoons. Safely colors water black while the enzymes help to create a healthy pond environment by digesting organic waste and reducing noxious odors. Specially Formulated for Reflecting Ponds. Additional Information: Will not stain. Safe for humans plants and aquatic life. Blocks out specific light rays. Digests organic waste. Reduces noxious odors No restrictions on swimming irrigating or fishing.