The koi pond is icing over, even with me prying up ice with the shovel--it ices faster than I can pry it off. I have bubblers, which are working again now that I have run miles of extension cord and are using 3 different outdoor plugs. The problem is the ice will grow around the bubbler intake tubes and choke them off, and then seal off the top of the pond, cutting off oxygen.
My Aquascape 2000 de-icer has been a great disappointment, to say the least--it does not play well with the GFIC receptacle it is plugged into. So I hauled it out this morning. I was planning on returning it to the store, only to find that the receipt had somehow been lost inside the turtle-like top of the de-icer, and then fell out..in the pond...and is now glued into the ice in the pond, about 2 inches under and one inch up.You can see it by my cat's foot, where he is stupidly standing on the ice
Anyway, the previous owner showed me the horse trough heater when she was removing some of her own stuff, and assured me it "worked great". It looks a little like the photo above as it sits on the pond, though the photo is of a dichroic glass necklace that I need to send to Mom (it's a Christmas stocking stuffer..or at this point a Valentine's present.) So the trough heater will either keep a hole open in the ice, or electrocute the fish, which will solve the problem one way or another.