This isn't discussed much, but I think it should be revisited for those that don't know.
Ground Fault Circuit Interrupter (GFCI) can potentially save your life, and truely is something that every aquarium tank should have.
How GFCI Works. For $30-40 from
online stores, or Hardware stores like OSH (Orchard), you can have one protecting your wet hands and body from electrical shocks.
Portable GFCI extention cord
Are your aquariums and you protected from those sudden power surges, and accidental falling lights in the tank? If not, I suggest you get one ASAP.
-John N.