Please don't buy fish to solve a problem.
Oto's will not clear all the algae, they can be quite picky, & can starve to death unless you feed them.
Try & find out why you have an algae problem first, are you leaving your lights on for too long, does your tank get a lot of sun etc
Oto's IMO/IME should be part of every planted tank (as long as it's bigger that 10g), along with amano shrimps. I'm a believer that every planted tank should contain a CUC as much as a marine tank.
Rams horn snails are the best cleaners you could ever have? I keep them in all my tanks and they are spotless I don't even clean the glass. I have mastered the art of a balanced tank it took years but I get it. With the help of my snails my tanks stay beautiful.
Ottos and shrimp like amanos or cherries if you would like to breed them. Ultimately, finding the root cause of the algae is the best method of keeping it away, but all my planted tanks have ottos and shrimp in to tidy up any bits that I've missed.