One caveat...........ADD AN ADDITIONAL SAFETY GROUND to your tank, I mean a big say, no 12 or so piece of wire BOLTED to the tank, and run to an UNBREAKABLE ground point. This is in addition to your "third wire" 3 wire plug.
WHY? Because those heaters can "leak" electric current between the element to the outer tube housing. That would make the tank "hot" above ground
