When trying to control algae in a natural way in a pond, many people look for fish or other lifeforms they can add to do the job. However, there are a limited number of fish, shrimp, and crustaceans willing to eat algae that also thrive in outdoor environments. Technically, carp and koi love to eat algae and may control it when added to a pond. Yet they need very specific conditions to stay alive, never mind thrive and actually grow. The common pleco, the mosquitofish, the Siamese algae eater and the grass carp are much hardier and tougher fish that will all eat algae when added to a pond.
Adding a few algae eating fish is likely not enough to take a pond from murky to perfectly clear. These fish only eat a limited amount of algae and can’t keep up with a pond that generates a lot of it. Don’t forget to focus on other methods of naturally reducing algae growth like controlling runoff from nearby lawns and fields. You can’t just keep adding fish to eat more algae because they’ll start overwhelming the pond with waste instead.
