Methods of harvesting algae, and using algae as a biofuel, livestock feed, or food supplement are provided. The methods comprise contacting liquid algae suspensions with a filtration media. Depending upon the filtration media, the resulting algae and filtration media admixture is then utilized as a biofuel, livestock feed, food supplements, or for the extraction of algae oil. Admixtures comprising a combustible filtration media, such as coal, are particularly preferred. The methods are suitable for use with any algae species. Compositions for use as a biofuel, livestock feed, or food supplement are also provided. These compositions comprise an admixture of algae and a filtration media.