Can you put an alge eater fish in a koi pond?

Yes, you can introduce an algae eater fish, such as a Plecostomus or a Chinese algae eater, into a koi pond. However, it's important to consider the size of the fish and the pond, as algae eaters can grow large and may compete with koi for food. Additionally, ensure that the water conditions are compatible for both species. Always monitor their interactions to ensure a harmonious environment.