Can plecos live with silver dollars?

Verdict
Yes

Yes. Plecos and silver dollars get along in the same tank. Both are fine at 75–82°F. Plan on at least 125 gal.

Common plecoCommon pleco72–86°F · pH 6.5–7.5 Silver dollarSilver dollar75–82°F · pH 5–7

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 75–82°Common pleco 72–86°Silver dollar 75–82°
The green band is the temperature range both can live in.
456789Both: 6.5–7Common pleco 6.5–7.5Silver dollar 5–7
The green band is the pH both tolerate.

Size to scale

Common pleco · 15 inSilver dollar · 6 in0"2"4"6"8"10"12"14"
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

Common plecoSilver dollar
Temperature72–86 °F75–82 °F
pH6.5–7.55–7
Adult size15.0 in6.0 in
Minimum tank125 gal75 gal
TemperamentPeacefulPeaceful
Swims atBottomMiddle
GroupAlone or in pairsGroups of 5+
DietHerbivoreHerbivore

Better tank mates for plecos

All common pleco tank mates

Better tank mates for silver dollars

All silver dollar tank mates

Questions

Can plecos live with silver dollars?

Yes. Plecos and silver dollars get along in the same tank. Both are fine at 75–82°F. Plan on at least 125 gal.

What temperature suits both plecos and silver dollars?

75–82 °F. Plecos need 72–86 °F, silver dollars need 75–82 °F.

What size tank do plecos and silver dollars need together?

At least 125 gal, set by the common pleco. Add space for each extra fish.