Can Guppy Live With Common otocinclus?

Small loricariids are among the fish guppies do well with, and the otocinclus is a small one: about 3.3 cm, peaceful, and busy grazing soft green algae and diatom film off glass and leaves.

The water works but sits near the edge for both. Otocinclus want 20 to 25 °C at pH 6 to 7.5 and guppies pH 7 to 8, so run the tank at 20 to 25 °C and pH 7 to 7.5.

Otocinclus bring one condition of their own. They need a mature tank with algae and biofilm already growing, because a clean new setup leaves them little to eat, and they can lose out to other feeders. Guppies are omnivores that take almost any food, so make sure plant-based food reaches the bottom as well. Check the otos' bellies: rounded is fine, while a hollow or pinched belly means starvation. Keep six or more in at least 60 litres.