I use an aquarium heater, too. The waterer is a 10L bucket. Only thing is, the lowest temp setting on a tank heater is like 20 or 22 degrees celsius so it probably uses more power than whatever other water heating devices are out there. I also noticed today that the water level had gone done immensely compared to non-heated summer water; so, either the chickies were hella-thirsty or an amount was lost to evaporation.
The stress from constant light mentioned in this thread: does it apply to infrared heat lamps? I've had mine on for the past two nights and was hoping to unplug it tonight, but we're having -18c with 92% humidity so unplugging it might kill the tiny white phoenix and maybe make some of the others sick? I know it's far too brutal for me to go outside, even bundled up like a siberian. The temp/humidity combo is equivalent to the -50/-60c that I experienced when I lived in bone-dry alberta. (Fyi, -65 is when people in alberta are warned not to go out due to instaneous frostbite on any exposed skin.) So I really hope I can leave their light on one more night without "messing" with them. I know the neighbourhood ducks are fine, but they're staying in the water - plus they're designed for wet (humidity) and so far everything I've seen here (byc) is chickens no humidity, must be dry! Advice?