Growing Tip:
Do I need to install a Ground Fault Circuit Interupt in my grow room?
-- Cultivation of Marihuana Factoid

Absolutely. If it is a hydroponics grow, there is no doubt that you need a Ground Fault Circuit Interrupter (Ground Fault Circuit Interupt). Likewise, any place where it is likely or possible that someone may be standing in a puddle of water and will come in contact with a plugged in electrical contraption needs a Ground Fault Circuit Interupt.