A one-gallon tank is usually considered to be too small to accommodate any fish because it does not provide enough swimming space and suitable water conditions. In addition, the presence of algae-eating fish in such a small environment could lead to overstocking and water quality problems.
Are there recommended algae eater fishes for small one gallon tanks with betta fish on it?
No, there are no algae eater fish suitable for one-gallon tanks.