Can I Add

[Timberview]

A pleco to my goldfish tank? one that will stay small and eat some alge?

 

[afishdude]

how big is your tank and what other fish do you have in it?

 

[black angel]

Get a thermometer if you dont have one and check the temp.

Bristlenose plecs can take lower temps but not below 18c. True coldwater loaches such as butterfly plecs must have cold water and a fast flowing part of the tank to replicate the fast streams they come from.