Dwarf fish which include Guppies and Danios, Corydora catfish, pigmy suckermouths, teams of barbs or tetras Most Central and South American cichlids could be held with a variety of aquarium crops, but African species are more difficult to pair because of drinking water parameters. It isn't really unattainable however! Check https://pearlaquatics.my/7-ways-to-keep-fish-pond-clean-healthy/