I tailor temps to where the fish come from in nature, and many areas can be different.
Uruguayans such as Gymnogeophagus, Australoheros and Crenicichla, no heaters at all, 60sF, night and winter temps can fall to high 50s
Northern Mexicans such as beani, carpintus and bartoni, high 60s, low 70s in winter, little higher temps in summer.
In fact my beani spawned at 70'F, and carpintus kept outside this summer reached low 60s with no ill effects.
Madagascans, Nandopsis from the Caribbean, northern S Americans, constant high 80s.
I find northern Mexicans are prone to hyper aggressiveness, Flexibactor and other infections if kept at constant 80s.
Just as haitiensus are prone to ich and bloat in the 70s.
When I've been in the Caribbean, fresh water temps I've checked have always seemed hot.
When in Costa Rica, or Mexico, river water temps always seemed to me to be surprisingly cool.