***Be sure to use a GFI plug with this!*** here is a link to the Through-Wall version http://community.theaquaponicsource.com/forum/topics/diy-heater-build-your-own-2000-watt-heater-for-20  COPPER WARNING! most of the elements are made from nickel plated copper and should not be used! I have not found stainless elements at Home Depot. Some of the Lowes stores have them. A quick search on the web …