Dwarf fish such as Guppies and Danios, Corydora catfish, pigmy suckermouths, groups of barbs or tetras species similar to the chili rasbora are one of many couple education fish that can thrive inside a 5-gallon aquarium. The copyright Gudgeon is one of those freshwater fish that have really vivid colours. https://pearlaquatics.my/nitrogen-cycle/