Many central Americans, JDs especially, come from murky muddy backwaters so in the wild they will be used to not a lot of light penetrating the surface. I currently have 80watts over my 300l as I only run two of the four bulbs. I am upgrading to led soon and may tone it down a bit more for my pictus and barbs.
As long as there is light in the room, fish dont need the tank light on all the time. It is just for us to view them. Mine is on 5 hours in the week days and 10 at weekend days.