GrowFAQ:

Do I need to install a GFCI in my grow room?

  Added by: Bongaloid  Last edited by: 10k  Viewed: 384 times  Rated by 3 users: 8.00/10
Absolutely. If it is a hydroponics grow, there is no doubt that you need a Ground Fault Circuit Interrupter (GFCI). 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 device needs a GFCI.
  Last modified: 14:54 - Feb 25, 2001 

faq:814 "Do I need to install a GFCI in my grow room?"