I've been thinking about bird bath heaters for this winter.
iwiw60 did you use this heater last winter?.....I think you only got your birds this spring?
One thing I'm wondering is how well will they work in deep water, like a 2-5 gallon bucket? Most bird baths hold only 2 or 3" of water, maybe 12-18" in diameter?
My 15 birds drink 2 gallons a day.....I guess I could bring out a gallon jug a couple times a day and refill the bucket.
Another thing that concerns me is that the heater linked above says not to use it with more than a 15 foot extension cord....and I have a 50 foot extension cord going out to my coop. Electrical resistance of the wires themselves can diminish voltage over distance, so may not deliver enough voltage/wattage to power heater.
Just some thoughts.......