My guess is that, in the wild, the temperatures in the South American rivers where angels and rams live don't fluctuate much from day to night. So I'd drop the temperature at night only very slightly, if I was to try this.
Maybe do some research on how much the water temperatures fluctuate?
According to this USGS report the Amazon river only fluctuates by 2 degrees F year-around(84-86 F). That's very surprising. However, the majority of these fish are coming form tributary's which I'm sure fluctuate more than that. For my stock I'm probably better off just maintaining a steady temp though, or no more than a few degrees day/night.
Last edited by silasvirus82; 11-07-2019 at 03:24 PM.