Penn Plax Aquaponic Betta Fish Tank Promotes Healthy Environment for Plants and Fish Plastic plant holder with ceramic substrate planting material. Planter can create a healthy habitat for betta fish by replicating nature's cycle. Plant above purifies water and absorbs fish waste as nourishment. Betta fish tank is easy to clean; planter is simple to remove when needed. Can be used as a planter alone for many water thirsty plants. Recommended for betta, goldfish, bloodfin tetra, and white cloud minnow.