If your convicts have no color to them,then they're stressed out.I recommend a Test kit today,instead of waiting.Temps should range around 78 to 82 degrees to be honest,that is why how I have mine set up for temps.
Mine normally only do this when the water is cooler but it could still be something else and they could even be taking a nap as mine do sometimes unless you are talking about they have been like this for most of the day.