Constructed wetlands with Canna indica and Oryza sativa L. were compared for removing heavy metals and nutrients from piggery effluent in Nigeria. Oryza sativa L. was more effective at removing pollutants than Canna indica. Oryza sativa L. accumulated more metals in its above-ground tissues, making Canna indica a better choice for phytoremediation. The study showed that piggery effluent had high levels of pollutants, indicating the need for treatment before reuse.