Seachem is probably our favorite brand of aquarium products. Everything they make is pretty darn good and Purigen is one of the staple products for keeping quality high. Purigen is a premium synthetic polymer that eliminates water impurities much faster than competing products. Along with regulating ammonia, nitrites and nitrates Purigen also polishes aquarium water making it crystal clear. Seachem Purigen is great for keeping Flowerhorn cichlids, add it to your filter media for added benefits.