Can Freshwater angelfish Live With Common otocinclus?

Otocinclus are small, peaceful algae grazers, about 3.3 cm long, and very small fish that may be eaten are the ones to avoid with an angelfish. That puts otos near the edge of what an angelfish tank can hold.

Temperature is the tighter limit. Otocinclus want 20 to 25 °C and angelfish 24 to 30 °C, so the two share only 24 to 25 °C. The pH overlaps from 6 to 7.5.

If you add them, keep six or more in a mature tank with algae and biofilm to graze, and check their bellies: a hollow or pinched belly means they are not getting enough to eat, a common problem in underfed groups. Otocinclus are herbivores, so a mature tank matters more to them than any feeding schedule, and the tall tank of at least 200 litres that an angelfish needs gives them plenty of surface to work.