Warning

I noticed that many pond keepers want to keep algae to a minimum by adding a janitor fish. This is a major disaster in my opinion. Hypostomus plecostomus, the suckermouth catfish or common pleco, is a nocturnal fish. They find their food while your koi are sleeping at night. They tend to suck at and stick to your koi’s body and fins. The next day, your koi may have injuries and will be severely stressed out. The common plecos also grow rapidly, outgrowing the pond and competing with koi in terms of nutrition and water requirements.