I am in need of a new pond heater for the pond in my newly-acquired home. Are the 100w de-icers efficient enough to keep the fish alive over a New England winter? I have both a 1250w and a 100w jobbie. I'd obviously like to use the one with a lower wattage (and buy myself a second one to save the pennies)... but am I fooling myself? Are they just a piece of junk? Hope you can give me some insight.
Thanks for writing.
I wish I could give you a definitive answer. I live in New Orleans and we don't exactly get frozen ponds. If your pond is below the frost line, you should be OK. Give the smaller one a try. If a hole in the ice stays open, you are fine. If not, try the bigger one. All it needs to do is keep a hole open.
If your pond has frozen solid in the past, then you must think about bringing your fish in for the winter because nothing will work to keep the water thawed unless you think about a swimming pool heater.