If you turn your Tablo off overnight, it cannot perform its nightly maintenance.
(According to Tablo Support one of your Tablo units hasn’t run maintenance for over a week.)
And while your Tablo won’t be overrun by gremlins from missing a handful of maintenance periods, as time goes by your Tablo’s database could eventually grow too large and cause significant problems.
And if you always turn your Tablo on during the busy evening watching/recording hours, you could also eventually run out of guide data.
That’s why we don’t recommend turning your Tablo off overnight.
If you do want to save some money/electricity, you can turn everything else off (Roku etc.) but make sure to leave the Tablo on at least a few nights a week.