i read that common plecos can survive down to 55 degrees F but anything below that they drop dead. ive also read alot of reports from around the world about people putting pleco(s) in their ponds and emptying their ponds a year later to clean them and they discover that their 2" cute plecos turned into 15" monsters! i considered putting a pleco in my pond (they are $35+ here in oz for a tiny common) and i bought one and put it in a growout tank and fed it algae wafers, and come home one day and find it dead! now their seems to be a price rise (now around $45, sailfin $90). after buying all these cichlids which are supposedly becoming illegal, i might get me another pleco, and put it in with my guppies (nothing seems to die in there)