That can still be considered tropical water temp. You do realize that plecos come from Central/South America... in Tropical environments don't you?Common plecos do just fine in water as cool as 67F, my question is: where did the REST of you get your information?
Here a simple link. http://www.planetcatfish.com/common/species.php?species_id=88
Show me one of yours(link) that says a plecos can survive in 49 degrees(non Tropical)