What is their native habitat and what are the seasonal temperatures there? Replicating that would be the best care for them.
Agree with this.
But you may want to find out the details of where your perch was sourced.
If sourced from Thailand, it will be warm water tolerant.
But if sourced in its northern range, places like sub tropical China or from Korea, it probably will not be warm water tolerant, long term.
Or will only be warm water tolerant for a certain seasonal time span
Its like certain fish in the US.
Sunfish or gars from Minnesota have evolved tolerance for cold, and require seasonal fluctuations to remain healthy, yet
sunfish or gars from Florida probably will not have evolved tolerance that cold, or require seasonal temp drops..
And It often doesn't matter what "we" as aquarists want, it matters how the species has evolved that determines what it tolerates or not.
I have found that most Gymnogeophagus from Uruguay require seasonal cool downs to remain healthy, because that is what occurs their natural habitat.
Gymoongeophagus such as balzani (if sourced from Brazil, where seasonal changes fluctuate less ) do not require those more drastic cool downs.
