Can otocinclus live with dwarf neon rainbowfish?

Verdict
Yes

Yes. Otocinclus and dwarf neon rainbowfish get along in the same tank. Both are fine at 75–79°F. Plan on at least 20 gal.

OtocinclusOtocinclus72–79°F · pH 6–7.5 Dwarf neon rainbowfishDwarf neon rainbowfish75–82°F · pH 6.5–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 75–79°Otocinclus 72–79°Dwarf neon rainbowfish 75–82°
The green band is the temperature range both can live in.
456789Both: 6.5–7.5Otocinclus 6–7.5Dwarf neon rainbowfish 6.5–7.5
The green band is the pH both tolerate.

Size to scale

Otocinclus · 2 inDwarf neon rainbowfish · 2.5 in0"1"2"3"4"5"6"
Adult length in an aquarium. A fish can swallow anything that fits in its mouth, roughly a third to half its own length for predators.

Care at a glance

OtocinclusDwarf neon rainbowfish
Temperature72–79 °F75–82 °F
pH6–7.56.5–7.5
Adult size2.0 in2.5 in
Minimum tank20 gal20 gal
TemperamentPeacefulPeaceful
Swims atBottomMiddle
GroupGroups of 6+Groups of 6+
DietHerbivoreOmnivore

Better tank mates for otocinclus

All otocinclus tank mates

Better tank mates for dwarf neon rainbowfish

All dwarf neon rainbowfish tank mates

Questions

Can otocinclus live with dwarf neon rainbowfish?

Yes. Otocinclus and dwarf neon rainbowfish get along in the same tank. Both are fine at 75–79°F. Plan on at least 20 gal.

What temperature suits both otocinclus and dwarf neon rainbowfish?

75–79 °F. Otocinclus need 72–79 °F, dwarf neon rainbowfish need 75–82 °F.

What size tank do otocinclus and dwarf neon rainbowfish need together?

At least 20 gal, set by the otocinclus. Add space for each extra fish.