I am totally lost. I cannot afford the $1200 thing I posted, and I do not understand much of what you guys are talking about. Right now I bought a UPC for my son for Christmas. However, he s already ready for a bigger tank. However, I cannot get him one until I can sort this issue out, as I cannot invest any more money in this hobby unless the tank is protected. Our tank is in our daily room, and there is no possibility of having an outdoor generator that is routed into the house like lucky Thang has. Can anyone explain a workable option to me that would power a 120G tank for a reasonably lengthy period of time and that can be inside a house-ie no gas, etc.?