[mike31154]

It will be helpful if you provide a little more information on how much equipment you currently have hooked up to your receptacle, i.e. how much total wattage. Most of your gear should be labeled as to it's max. wattage draw. However, in any case, running your entire system on a single receptacle is not a good idea in the long run. You're relying on a single circuit, probably the standard 15 amps and if that breaker trips, all your equipment shuts down. So unless you have an automatic back up system, or you're at home when it happens, this could spell trouble for your tank. Furthermore, that 15 amp circuit undoubtedly supplies a number of additional receptacles, either upstream or downstream. It's also a good idea for the circuit supplying your tank equipment to be protected by a GFCI, particularly the items submerged in the water such as your heater and any power heads.
One of your options could be to buy a GFCI power bar/extension in addition to running an extension cord to the outlet across the room. However, if the outlet across the room is wired to the same circuit breaker it will be counterproductive since you're just adding more wire (read resistance) to the existing circuit.
If you're the homeowner, I would recommend looking into how your room is wired and adding at least one more circuit on another breaker. If you're renting, not sure what can be done other than running a large guage extension cord from another room, making certain it's on a different circuit breaker.