Unique betta fish tanks. The EcoQube is only about 2 gallon in size. 02.04.2018 Nalkis I will use again. I divided the tank with a tank divider, bought at a local pet store. The most important factor to your fish aquarium succeeding is having beneficial bacteria. Extended red is an intense version of red, that covers the betta from head to tail, included pectoral fins fins on the side of their body. Tetra 1. The most important factor to your fish aquarium succeeding is having beneficial bacteria. Kristin Mayfield. They are in small tanks till this weekend when I finish my 20 gallon with dividers for them.