You NEED to get one of these ASAP! (GFCI) This should be considered mandatory, in fact where I live the electrical code says it is mandatory on bathroom and kitchen circuits because of the proximity of water.
Also, you only need one per circuit. So if your tank is on the same circuit as a GFCI outlet you do not need another one near the tank, even if the GFCI outlet is in the other room. If you have two, you may run into a problem where the GFCI keeps tripping for no reason. Happened to me
Thanks to my brother the electrician I removed the second one and presto no more trips!
GFCI = ground fault circuit interrupter
From Doityourself.com
Have you ever experienced an electric shock? If you did, the shock probably happened because your hand or some other part of your body contacted a source of electrical current and your body provided a path for the electrical current to go to the ground, so that you received a shock.
An unintentional electric path between a source of current and a grounded surface is referred to as a "ground-fault." Ground faults ground-fault. Ground faults occur when current is leaking somewhere, in effect, electricity is escaping to the ground. How it leaks is very important. If your body provides a path to the ground for this leakage, you could be injured, burned, severely shocked, or electrocuted.
In the home's wiring system, the GFCI constantly monitors electricity flowing in a circuit, to sense any loss of current. If the current flowing through the circuit differs by a small amount from that returning, the GFCI quickly switches off power to that circuit. The GFCI interrupts power faster than a blink of an eye to prevent a lethal dose of electricity. You may receive a painful shock, but you should not be electrocuted or receive a serious shock injury.
Availability of GFCIs
Three common types of ground fault circuit interrupters are available for home use:
Receptacle Type: This type of GFCI is used in place of the standard duplex receptacle found throughout the house It fits into the standard outlet box and protects you against "ground faults' whenever an electrical product is plugged into the outlet Most receptacle-type GFCls can be installed so that they also protect other electrical outlets further "down stream" in the branch circuit.
Circuit Breaker Type: In homes equipped with circuit breakers rather than fuses, a circuit breaker GFCI may be installed in a panel box to give protection to selected circuits The circuit breaker GFCI serves a dual purpose - not only will it shut off electricity in the event of a "ground-fault," but it will also trip when a short circuit or an overload occurs Protection covers the wiring and each outlet, lighting fixture, heater, etc. served by the branch circuit protected by the GFCI in the panel box.
Portable Type: Where permanent GFCls are not practical, portable GFCls may be used One type contains the GFCI circuitry in a plastic enclosure with plug blades in the back and receptacle slots in the f rant. It can be plugged into a receptacle, then, the electrical product is plugged into the GFCI. Another type of portable GFCI is an extension cord combined with a GFCI. It adds flexibility in using receptacles that are not protected by GFCls.