I need to keep a 1000 gallon outdoor concrete tank from freezing down to 0 degrees F. I see most immersion heaters provide a KW rating but I don't know how to determin the power I need. thanks
Presumably, you can calculate the heat loss from the tank in terms of btu/hr or calories/hr then apply the conversion factors to determin Watts or Kilowatt which should be the rating of the electric heater. Dont forget to apply a fudge factor to your final value.