Well. because we've been there. The snow falls, or the rain, the temps drop and there's not much you can do about keeping your Tropical Fish alive besides heating them! After losing enough fish we got a, well, Rallysman explains it well. rallysman said:actually, after doing some math it would probably be cheaper to get a generator to run the equipment for any amount of time. a UPS is great for short term, but long term would be expensive to get one large enough to do any good