Can you put an otto catfish in a 5 gallon tank?

No, an otto catfish (Otocinclus) is not suitable for a 5-gallon tank. These fish are social creatures and thrive in groups, ideally requiring a minimum of 6 individuals, which would be difficult to accommodate in such a small space. Additionally, they need stable water conditions and ample plant cover for grazing, which can also be challenging to provide in a 5-gallon setup. A larger tank would be more appropriate for their well-being.