Can otocinclus live with silver dollars?

Verdict
Yes

Yes, otocinclus and silver dollars can live together. Both are fine at 75–79°F. Plan on at least 75 gal.

OtocinclusOtocinclus72–79°F · pH 6–7.5 Silver dollarSilver dollar75–82°F · pH 5–7

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 75–79°Otocinclus 72–79°Silver dollar 75–82°
The green band is the temperature range both can live in.
456789Both: 6–7Otocinclus 6–7.5Silver dollar 5–7
The green band is the pH both tolerate.

Size to scale

Otocinclus · 2 inSilver dollar · 6 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

OtocinclusSilver dollar
Temperature72–79 °F75–82 °F
pH6–7.55–7
Adult size2.0 in6.0 in
Minimum tank20 gal75 gal
TemperamentPeacefulPeaceful
Swims atBottomMiddle
GroupGroups of 6+Groups of 5+
DietHerbivoreHerbivore

Better tank mates for otocinclus

All otocinclus tank mates

Better tank mates for silver dollars

All silver dollar tank mates

Questions

Can otocinclus live with silver dollars?

Yes, otocinclus and silver dollars can live together. Both are fine at 75–79°F. Plan on at least 75 gal.

What temperature suits both otocinclus and silver dollars?

75–79 °F. Otocinclus need 72–79 °F, silver dollars need 75–82 °F.

What size tank do otocinclus and silver dollars need together?

At least 75 gal, set by the silver dollar. Add space for each extra fish.