Fritz Crystal Clear rapidly clears water by pulling together (flocculating) fine particles; allowing them to be removed by the filter or settle to the bottom; leaving your aquarium crystal clear. Fritz Crystal Clear will not affect bio-filtration; pH or other important water parameters like other brands. Safe and effective for use in freshwater; saltwater; reef aquariums and ponds. 100% phosphate free; safe for all fish and plants and invertebrates; will not contribute to future cloudy water problems.