Nutrafin Bio-Clear Biological Water Clarifier. Nutrafin Bio-Clear biologically clarifies cloudy aquariums caused by new-tank syndrome, excess food, organic waste, decaying plant remnants, and other issues. Bio-Clear uses a responsive enzyme-based formula that eliminates milky, cloudy aquarium water due to organic causes within 24 to 48 hours. For use when water is cloudy due to excess organics Combats "New tank syndrome" For freshwater use only. Available Size: 120 mL (4 fl oz)