In your area, you will probably need something more than a DIY de-icer to keep a hole in the ice open. If the ice closes over, toxic gasses build up under the ice and that can kill fish. Also, get the bottom of your pond as clean as possible before winter to minimize decaying materials which will cause water quality issues, especially in late winter and early spring. Have you thought about putting a simple DIY greenhouse over the pond for the winter?

I use an air pump with two sets of tubing and two air stones about 12" down to run a bubbler and I lower my pump under the surface and let it run all winter.

The pump is in the middle of the pond and the bubbler is off in one corner. Two holes open when I get ice. The hole varies in size depending on the weather but never has closed up completely.

If I lose power all shuts off but power comes back on here after a few hours or a few days depending on how bad the situation that caused the outage in the first place.

Comettose.....yes, I didn't mention the power issue. We lost power for almost a week last year. I am hoping this winter will be back to normal but one never knows in this state. On the bubbler....is yours one that you would use in a home fish tank?? I have one of those with two lines w/stones but it doesn't look nearly large enough to keep the ice from building up. Our pump is hooked into a filtering system at the bottom of the pond. We also have a uv one above ground. We disconnect both of those. so if I understand you I just unhook the waterfall and use the pump w/out the filters and also use the bubbler? Our pump is on a timer which it will stay on.

ccoombs......... I'm not sure how a greenhouse would work here. If I put a frame w/plastic up the wind,snow and ice would have it in the next county within hours. Do you think maybe we could use a screen with a piece of plywood over part of the pond...thinking it might help hold the heat in.

It can be brutal here but ideas can always be modified.
thanks, anymore ideas will be welcomed

LOL! A week? that hurts. When we had an above ground swimming pool up in Wisconsin we had an inflatable pillow that was anchored just below the float level. As the water froze, the pillow was squeezed but didn't let the ice close it off entirely. It sounds strange but the pool survived 8 years with no ice damage. A friend used an innertube. Sandy

Sandy - floating objects - I've seen that recommended (a log, a large piece of styrofoam, a basketball)

Maggie - raise the pump up off the bottom and place it soundly on a solid stack of bricks or a cinder block so the outlet is below the surface of the water (say about 12" or less) where it will make the water turbulent. You may want to have your pump within reach in the event you want to pull it for any reason.

My bubbler is made from a two outlet Wal-mart aquarium air pump. I use silicone tubing (more cold resistant), two reglar blue airstones, and two backflow devices. I twist the tubing together most of the way down so the air stones stay close to each but not touching. The air pump is not waterproof so I bought a clear showbox/storage box with a lid and cut small holes out of one end for the tubing to pass through on the other end a hole for the electric cord to pass through. The air pump stays inside the plastic box which keeps water out. The hole box is sitting on a large brick, wrapped in a scrap piece of liner, and another big brick on top to keep it secure all winter. It sits next to the pond and sometimes gets buried under snow or rained on.

Moving water doesn't freeze as quickly as still water and both the pump and bubbler move the water.

I've also used a ThermoPond before for a few years but it died on me, but in your zone I would consider some type of de-icer as well and some type of snow deflecting cover that will allow sunshine in but cold blowing wind out.

I have not tried it but I've always toyed with the idea of putting plexiglass over a corner of my pond to see if the sun shining in will create a greenhouse effect during the day in THAT corner. The whole pond does not have to be protected, but enough to keep a hole open all winter. You also don't want your pond to freeze to the bottom.

Horton has a good set up for cold blowing winds. Maybe he will chime in.

If you put anything over the pond such as styrafoam, plexiglas or plywood, make sure it is far enough from the water surface that the fish don't decide to jump on top of it. I bought a beautiful little harikwae a year or so back. His pool was hot and sunny, so I decided to shade it by laying a piece of styrafoam on it. I found the little fish dried out in the sun, laying in the middle of the foam. Pretty sad.

My pond is 7 foot radius semi-circle with about 1100 gallons. Its 3' deep in the centre and nowhere less than 1' deep.

First thing I do is I shut down my biofilter and take my pump out of the pond. Turn off pump, clean prefilter, pump, biofilter, and place pump in bucket of clean water with loose lid to store over winter indoors. I put a plastic sheet over the biofilter secured with bungee cords to keep water out of the filter over winter.

Then I pull all of the plant pots out 1 by 1 and cut off the tops of the plants that will freeze anyway and then check out the roots to make sure they have enough room in the pot and either prune, repot, or start an other one by splitting the root.

With all the pots out, I use a fine mesh net and get all of the leaves I see. Then I dredge the deepest portion of the pond with the net and normally get a lot of leaves and gunk that has settled over summer. When I'm satisfied I've removed as much of the debris and gunk as I reasonably can, I put the plant pots on the 2' and 3' levels. Then I set up an airstone in one part of the pond and a thermopond de-icer in another. This leaves air going into the pond, some circulation, and a hole for noxious gasses to escape. So far, I have always managed to keep the fish over winter but there are occasional deaths in early spring after ice out.

I do what kalevi does, but this year I'm using a tank heater instead of a 100w de-icer, and sheltering 3/4 of the pond from our freezing winds with a piece of plywood or foamboard. Last year we had no snow cover for insulation and my de-icer froze over for almost 3 weeks in Feb. Not good for the fish :(

Thanks for all the suggestion We were thinking plywood too on part of the pond. I know this pond has too many fish now, lots of babies, Started out with 13 two yrs ago and now I'm thinking there are around 30. Most babies and teens. I know they won't all survive but would like to keep the big ones. They are so tame they come and eat out of our hands. So much fun to watch when we have our coffeetime or just sit and take a break. I'll clean the pond and exchange the water and with all your advice...hopefully my husband will be able to watch his fish and I can watch the fogs next year.
Thanks so much

Best forum I've found about this interesting and timely subject! Who has experience with the greenhouse-over-your-pond winterizing technique? Assuming there is a 'hole' for gas exchange to take place, wouldn't a well-sealed (not totally airtight) greenhouse - to maximize solar energy helping keep the ice at bay and to keep the freezing wind out - need some intentional ventilation? Question is, how much - what turnover of greenhouse volume in what amount of time?

Where I live is cold enough (Zone 3), right next to Yellowstone National Park (often one of the coldest places in the US) but the windchill can get to -50F easily, so this is mainly what I want to protect against sucking the ground heat out of the water. My pond is 2,500 gallons almost 5' deep, but part of it (up to 1/3) is above ground, the lower walls made with what came out of the hole (where I live nothing is flat, either.)

I plan to use a Pond Breather (http://www.bestnest.com/bestnest/RTProduct.asp?SKU=API-8PB ) and this should keep the gas exchange going despite temperature and any ice. To create some air exchange inside my floating greenhouse (floating in the main part of the 7'x10' pond because the border is far too irregular, rocky and steep to build a greenhouse around) I am planning to use a Super Luft Pump (1.34 cfm air output) placed outside the greenhouse (i.e., fresh air) fed directly by tubing to the Pond Breather's gas exchange cap inside the greenhouse. This volume of air will create a turnover inside the greenhouse about once an hour, and with the freshest air being fed right to the hyperlimnion through the Pond Breather. (You have to understand how that works, it's different than a de-icer and not a heater.)

If anyone is still with me, do you think this will work? Is it enough air, too much, unnecessary?? I have 30-40# of comets, shibunkins and 3 koi, plus babies. I know about 6ppm dissolved oxygen levels, and I know 'goldfish' use 15-20% of the O2 in frigid winter water as in warmer summer water. These fish have all made it through smaller ponds for 10 Montana winters, but I am not trying to heat this one (just to 36F) - way too much water.

Hmmm Thanks for your thoughts and experience. Ron

Nuts. I just did a search for Greg Bickel's site to reccommend his DIY disk. Can't find it!! All I can locate is my own reference to it in a thread last year and a publication for Amazon Adventure that shows his greenhouse and the floating greenhouse. Does anyone know where he is now? Sandy

Here is a link that might be useful: floating greenhouse plan

Oops. It is Victoria Adventure not Amazon Adventure. Sorry, Sandy

I posted this for you over in Conversations, too, Sandy. :)

Brenda

Here is a link that might be useful: Bickal's stuff

I use this bubbler to keep my pond open in the winter. Works great here in NY. Thanks to David Hemenway. easy directions, inexpensive, good pictures of his example, expense comparison to other deicers.

Here is a link that might be useful: Hemenway's bubbler pages