I'm not sure what to make of this I put in a new Pond past year with a bog it's about an eight by nine 800 gallon 3 feet deep. The first winner I had the warmest pond water temperatures that I have ever had now mind you I have gone from a hundred gallon pond to an 800 gallon pond at first I thought it was because of the depth. But was still very shocked throughout the winner even during the polar vortex temperatures never dipped below 48 degrees. The only thing that I can actually attribute this too is that I cover the pond with lattice that is covered in plastic like for greenhouses I thought maybe I was creating a greenhouse effect for my pond I even had daylilies growing under there throughout the winter in Northeast Ohio kind of blew my mind. So I tried an experiment with the Frog Pond which was just a hundred gallon preformed pond that I placed in the back perennial gardens I was able to get electric there so I was able to run a bubbler through the use of extension cords for outside buried under mulch. So I did the same thing because I wasn't sure if the bubbler would continue it always quits on my koi pond but the koi pond is not completely sealed with plastic the edges are open about 2 to 3 in around the entire pond. So I covered the frog pond 100 gallon pond with a small bubbler with a piece of lattice and 3 Sheets of plastic for Greenhouseeffect. The bubbler machine is under the plastic next to the pond with very little tubing 2 create a Greenhouse effect. with my hopes to prevent the little frog pond from freezing. My little grandson would be so disappointed if his frogs died. To my surprise checking on it throughout the winter the bubbler never stopped not even during the polar vortex there's no heater in this pond No pumps nothing just rocks and bubbler. It created almost like a teranium affect where it would warm up during the day creating condensation on the inside and then dripping water back into the pond I didn't lose any to evaporation I was totally amazed at the outcome it may consider doing that with my koi pond next year as the bubbler always freezes up. I have even considered maybe doing it over the entire area on keeping the bog running not sure about that one though was afraid of ice dams. at 50 degrees all winter long I even had to feed my fish two or three times this year because of temperatures were above 55 I think it's creating a kind of microenvironment but it definitely was very surprising to me. Anybody else cover their ponds in this manner I learned this trick from a lady who doesn't up in Canada over her pond so that she never gets them iced over it's pretty effective as long as you're Pond is not too large.