I have tried the "gycerine" routine and used 5 capfulls from the little bottle my wife uses in cake making. It seemed to help some. Though there has been ice it is not frozen solid. I have one red heat light near the top of my coop and so far have had not rock solid situations. Maybe once. I have used the hot water method a few times and have gone out and filled them twice or three times in a day. I usually filll them at night around 6pm. I have a small red wagon that I drag everything to the coop with, so there is no back and forth. Also I have chronic tendenitis in both hands so it makes things doable. I use the "red" gallon jugs and use milk jugs to keep the water from spilling on the way to the coop. I also can add vitamins on occassion. I have spare jugs so I can wash them inbetween fillings. Chickens backwash, yuk. Oh I do have a white heat light on in the coop during the day, goes on in the morning and is turned off at night.