Can rams live with otocinclus?

Verdict
No

No. Rams and otocinclus should not share a tank. No shared temperature. Rams need 80–86°F, otocinclus need 72–79°F.

German blue ramGerman blue ram80–86°F · pH 5–7 OtocinclusOtocinclus72–79°F · pH 6–7.5

What to watch

What works

Water side by side

55°60°65°70°75°80°85°90°German blue ram 80–86°Otocinclus 72–79°
The ranges do not meet, so one of them would always be too warm or too cold.
456789Both: 6–7German blue ram 5–7Otocinclus 6–7.5
The green band is the pH both tolerate.

Size to scale

German blue ram · 2.5 inOtocinclus · 2 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

German blue ramOtocinclus
Temperature80–86 °F72–79 °F
pH5–76–7.5
Adult size2.5 in2.0 in
Minimum tank20 gal20 gal
TemperamentPeacefulPeaceful
Swims atBottomBottom
GroupAlone or in pairsGroups of 6+
DietOmnivoreHerbivore

Better tank mates for rams

All german blue ram tank mates

Better tank mates for otocinclus

All otocinclus tank mates

Questions

Can rams live with otocinclus?

No. Rams and otocinclus should not share a tank. No shared temperature. Rams need 80–86°F, otocinclus need 72–79°F.

What temperature suits both rams and otocinclus?

None. Rams need 80–86 °F and otocinclus need 72–79 °F, so the ranges do not meet.

What size tank do rams and otocinclus need together?

At least 20 gal, set by the german blue ram. Add space for each extra fish.