This is a 10 gallon tank. I’m trying for a low-tech semi-Dutch style. I did recently add the Fluval mini CO2, but it’s a very gentle CO2 system that I’ll gradually remove once the plants are grown in well. I’ve had the tank a long time, but I rescaped it (from a jungle) just a couple of months ago. It has a little filter and a cheap light that actually grows plants pretty well. The tank contains 1 female betta, 3 male N class Lime Green Endlers, 4 Gulf Coast Pygmy Sunfish (unfortunately all male I think), and Cherry shrimp. Oh, also an Oto (temporarily).