An electric dryer will suck up some juice as will a water chiller/heater. Electric water heater, dish washer, oh the list goes on. A small fish tank with flourescent lights is probably the least of your worries.
What you all CAN do is go around the house and change every single lightbulb with those 13 watt power compacts. I purchase them at Dummy Depot at $10 for six bulbs. Sure, it took over 20 bulbs to get the entire house, but I started saving money after about 2 months.