So called "Modern" Stainless steel heaters still use a basic resistive wire heating element so I doubt if they are any more efficient that older versions to be honest. Electric heating is cheaper to install that gas heating but more expensive to run. That said, on a well insulated 2000 gallon Koi pond, a 2KW heater, used sensibly should be fine.
Alan
Posted on Oct 28, 2005, 10:41 AM from IP address 213.120.101.21