In realty Plecos unless the temperature of your pond can support him all year around should not go into a pond , they are after all classed as tropical fish dp I have to agree with you it stands to reason that you let him come up to room temperatureand not to add warm wter to the cold.
Then Jon should set about adding a heater adding a heater to the container, then to bring him up a degree at a time until the tank reaches the correct temperature to support it correctly and personally next year keep him out of the pond and in doors
Dave
Then Jon should set about adding a heater adding a heater to the container, then to bring him up a degree at a time until the tank reaches the correct temperature to support it correctly and personally next year keep him out of the pond and in doors
Dave