Planted Tank Guru
Join Date: Jul 2010
Location: British Columbia, Canada
Not meaning to put down hobbyists who keep discus @ temps of 78 to 80F.
Apparently many do.
However, at those temps, discus' appetites do decline to an important extent, and over time, they tend to undergo stress. Many will eventually fall victim to a weakened immune system, sicken & perish.
I believe it was H. Axelrod, noted discus expert, who ran long term studies on discus behavior at various temps, and concluded that keeping discus @ 79 F or less would prove fatal over time.