A few things that are always handy are those battery operated air pumps that will help with surface agitation and circulation. Another trick is when it gets hot, put some ice in ziplock bags and put them in the tank to cool the water, make sure the bag doesn't leak the ice water into the tank, unless its filtered. also even a battery operated fan to blow across the surface of the water will help. also if you can let some sunlight into the room to help illuminate the tank, that may help get some light to your corals if the power is out. another trick is buy a marine/boat deep cycle battery that lasts longer than car batteries and get a power inverter that can handle the wattage from a power head so it can help with water circulation, which is a backup I have. if the battery dies out, you can always hook it up to your car and charge it back up if the power is out. those are a few tricks I have learned. oh and of course, stock up on fresh new saltwater and rodi. since the ammonia levels can rise without any means of filtration, water changes will be a must. also get some seachem prime, the ammonia remover, it helps from what I have heard.