I have a 500VA battery backup on my bigger filter & the heater which should run for about an hour or more.
Beyond that a blanket over the tank would help keep the temp up.. hope there aren't any more 24+ power outages.
120 Gal SW, 150lbs Prem. Fiji, 23Gal Sump, 2x250w 15K MH, 4x65w Actinic
3 x Halichoeres Chrysus (1 surfed), 3 x Nemateleotris magnifica, 1 x Centropyge bicolor, 11 x Scarlet Hermits, 6 x Zebra Hermits, 40 x Astrea Snails, 6 x Nassarius Snails, 3 x Cerith Snails