Emergency back up batteries

APC is one of the best known makers of UPS battery backups. Check out there web site APC - Smart-UPS XL - Product Information There is a chart here where you can choose the number of watts of power you need and the amount of back up time that you want. If you choose 300W (to run a skimmer, heater, and power head) then you are looking at around $1000 for 1 hour of backup time. These devices are good for limited power demands for short periods of time. They can give you a few minutes to save a file on your computer when the lights go out. If you can afford it, an emergency generator is a much better choice for reef-tank piece of mind. This site has lots of generators Electric Generators Direct - Your Portable Generator Superstore and Home Standby Generator Superstore - Power Generators, Gas Generators, Home Generators, Backup Generators, Electric Generator, Portable Generators, Power Generator, Gas Generator, Eme and you might be able to find even better prices elsewhere. You can get an 8000W standby generator and transfer switch for under $2000 (installatioin additional). IMHO, a standby generator with automatic transfer switch is a much better way to go than the kind of generator that you need to fill with fuel and hookup yourself whenever you need power. With these, bad things can happen if you aren't around to fire up the generator for a while when the power first goes out.

 

I just got my Kohler 17 kW generator hooked-up last week. We already had a 5 hour power outage that occured while we were away form the house. I swore to my wife that we were not going to set up a reef again until we had a stand-by generator. On the plus side, 17kW runs my well pump and HVAC as well.

 

How much money do you want to spend and do you have a gas line to your house?
Ideally if you have the means I would get a generator tied to a gas line that can power the whole house. Temporary outages for a few hours I can run my tank from an inverter from my car. My Lamborghini has a built in standard AC plug but, you can buy them cheap to plug into your cigarette lighter.
(did I say lambo?. .. i meant toyota)

 

This is what I have. Its rated up to 2000 watts. I can run my entire 200 on it.
Steadypower.com - Honda EU2000

Now, if you have a smaller tank, and even more so if you don't want to run the lights, you could go much smaller. Honestly, I would. I had this one for other uses, so it just kind of became the tank generator.
I have never had the power out for more than 30 minutes, and typically the storms that cause blackouts around here are in the summer, so I have never HAD to use any of my back-up sources. But I have tested them

 

All in all, good info guys and gals. It really depends on what your needs are and from there that is where you start.

 

My power rarely goes out here in Dallas. When I lived in Florida it went out all the time and would stay out for hours. If I lived somewhere where there are ice storms or hurricanes and such that the power can be off for a day or two I would really check into a generator that can run it all idea.

 

Last year right before hurricane season hit Florida, the North Florida Marine Aquarium Society (NFMAS) had a monthly meeting and the topic was Hurricane Preparedness. What it covered was ways to deal with power outages and some of the options that you have to deal with it. Rather than copy/paste it all here, this is the link to the thread that lists all of the information. It covered everything from battery powered air pumps all the way to full house automatic generators. While not everyone is at threat of a hurricane, everyone is at a threat of power outages and that is the biggest part of the meeting (other than to get the hades out of Florida when they came).
Hurricane Preparedness

 

To me there are two levels of backup, one is just bare minimum life support, maybe a powerhead for circulation and maybe an air stone just to keep oxygen up which I believe is one of the first things that can kill livestock and is pretty easy to do since powerheads don't use a ton of wattage.
Xantrex Technology Inc. - Mobile Office - PowerSource 400 - Product Information
Ecotech Marine Vortech Battery Backup

If you want/need to run things like your return pump, heater/cooler etc then you need something more significant like a generator or an inverter that you can hook up deep cell marine batteries to for example.
Inverter
PowerVerter® APS Inverter/Chargers (110-125V)
Some generators
- Harbor Freight Tools - Quality Tools at the Lowest Prices
ETQ Portable Generator — 1200 Surge Watts, 1000 Rated Watts, Model# TG1200 | 1,000 - 4,999 Watts | Northern Tool + Equipment
All Power America Portable Generator — 2000 Surge Watts, 1650 Rated Watts, Model# APG3010 | 1,000 - 4,999 Watts | Northern Tool + Equipment

Honestly I wouldn't run non-essentials like a skimmer or any reactors or even the lights for the first day or so. Coral will be fine without light for a day or two. Unless you have a really big generator like Packleader of course.