Can cardinal tetras and otocinclus live together?

Yes

Cardinal tetras and otocinclus can share a tank. Their water needs overlap and neither is known to bother the other.

Cardinal tetra Otocinclus

Why

  • Their temperature and pH ranges overlap comfortably, and neither is known to nip, chase or eat the other.

What each one needs

Cardinal tetraOtocinclusBoth
Temperature73–84°F (23–29°C)72–79°F (22–26°C)73–79°F (23–26°C)
pH5.0–7.06.0–7.56.0–7.0
Minimum tank20 gal (76 L)10 gal (38 L)20 gal (76 L)
Keep at least64
Adult size2 in (5.1 cm)1.8 in (4.6 cm)

The smallest tank for both

A 20 gallons (76 L) tank holds 6 cardinal tetras and 4 otocinclus at about 50% of its stocking limit, which leaves room for more.

Other tank mates for cardinal tetras

Other tank mates for otocinclus