You can buy yourself a small portable generator of if you can't afford one you just need to agitate the water every few hour to keep it aerated and displace the gases a large wooded spoon will do the trick.
Computer back up battery. Works well with smaller tanks. My power went out for a little over an hour and it kept my smaller tanks running. The backup on my 150 ran my little giant sump pump for about a half hour or so...still need to make sure only necessary stuff is on the backup outlets.