You could always put a tarp over the plywood. I have done that for quite a few years. The plywood should last for a few years if you do it that way. I bring my fish inside for the winter but leave my lilies in the pond and do that to help protect them and keep stuff out of my pond.

Thank you maet ! Tarp on top of plywood is a good idea, I will try that. I have too many fish, can't bring them inside. As long as I can keep a hole open, they seemed to be OK.

Plywood will buckle especially with water under it.I put a piece over chicken run for shade in 3 months you should see it.

What worries me is the wind catching an edge and tipping it. I've got other concerns but then I'm over cautious.

Many people make a structure made from pvc pipe to support net during warm weather and tarp or other plastic in winter. The pipes are flexible, so you can arch them over your pond and hold the pipes together with those plastic slip fasteners or even wire twistems. The arched form is very stable and allows snow to slip off before it gets too heavy. Of course, snow is a very good insulator, so some on the cover is good. The picture in the link below is not the nicest-looking such structure as I have seen, but if you read the thread, you will find out it works very well.

My pond is very small, and the pipes wouldn't bend enough to make a small cover, so I had to cut and join the pipe to make the frame of a little "house." I'm in FL, so I don't have to worry about freezing, but I wanted to control the swings in water temperature. So I put the plastic over the frame whenever the air temperature drops below 50F. It seems to be working pretty well.

Here is a link that might be useful: link

Sorry I forgot to add that I lay pieces of 2x4 or 2x6 (whichever I have) across the pond before I put the plywood on. The tarp that I use is actually very heavy, You would probably need to lay something on top of it tho.

My hubby built me a struture of bent pipes up over the pond with netting over all to keep herons out.I WANT TO COVER ONE END SO THE FISH CAN HIDE THIS WINTER.Not sure how yet.

sleeplessinftwayne: I worry about the wind too. It's very windy here. I plan to put something on to weight it down. What are the other worries you have?

sharon_9_fl: I love the idea, I can use it for my veggie bed. How do you fix the tubing to the ground?

maet: Thanks for the tip of using heavy tarp. I also plan to use 2X4.

Instead of the pipes going into the ground, you could drill some holes in a bigger pipe, stick the ends of the skinny pipes in, seal it and create a floating structure.

I don't have crazy winds like some of you do but if the structure itself is just a dome, and isn't very high I would think it wouldn't tip over.

Go to any hardware, garden, or home improvement store and ask for a screw-type ground anchor. They're used for lots of things like supporting young trees. They screw into the ground and have a large eye at the top for fastening. Screw them into the ground at the corners of your pipe structure and tie or clip the structure to the anchors.

You mention a heater but no reference to a good bubbler. A good set-up will keep a hole open all or most of the time, eliminating or at least minimizing fish loss. Easier than an elaborate cover.

For those with covers, do they absolutely prevent freezing, and if not isn't it still necessary to keep an area open? Just wondering.
Mike

beck_wi & sharon_9_fl: Good ideas! I am going to the store to check out the parts and to figure out which one is easier and less expensive for me to implement. Hopeful, easier and less expensive are not mutually exclusive:-)

Mike: I plan to use air pump, I think it's the same as your bubbler. Maybe air pump is not the right name? One of the mistake I made last year is not using an bubbler. This year, I am going to use de-icer and bubbler, plus a partial cover. The purpose of the cover is not to prevent freezing, it's to prevent snow falls on the de-icer and bubbler opening to seal them off. We had over 2 ft of snow in one sitting last winter, de-icer was completely sealed. After I cleaned the snow off the de-icer, the thawn-freeze cycle of nearby snow sealed off the de-icer again, that's what killed my fish. I am hoping this partial cover will keep the de-icer snow free.

By the way, should I use air stone or just a tubing with the bubbler? Is one better than the other?

Sara--I used a two outlet air pump, ran two tubes through a styrofoam block and attached long air stones. They hung down through the first foot or so of water. I also made a third hole in the styrofoam and affixed a pipe anchor to ensure constant bubbling in one location. The cord holding the anchor came up through the styrofoam with a large loop on top that I could hook to place the system out in the pond, adjust location if necessary, and retrieve in the spring.

Per convention I put the air pump on a piece of insulation in a Tote box. The hole necessary for the plug provides adequate ventilation. I put it on my dock to avoid direct contact with the ground. A little weight on the top to hold it down, and it is that cheap and easy.

I am near Pittsburgh and we also had a very cold and snowy winter. The large hole never froze and snow melted in the open water. Your heater makes a perfect back-up--unless the power goes out--then its boiling water!

A cover is a good idea if you can support it with a heavy snow load as you describe. My pond is a bit large and oddly configured so I am dependent on the air pump. I am no expert on this, but it seems when you have fish in a still body of water some bubbling is healthy.

Good luck and be sure to let us know how you finally end up fabricating the cover and pictures would be wonderful.
Mike

I made one similar to the link Sharon gave. It worked out pretty well, but I "overbuilt" it and I am going to re-do it in a smaller version. A few things that will help out. I used 1" PVC pipe. If you are doing a lower version like the one in Sharons link, 3/4" will be enough. Use as thick of plastic as you can. I used 6 mil. and get the duct tape that is heavier for outdoor use if needed. I haven't even covered my stock tank filter, totally sealed the structure or shut down the falls yet but the temp. is staying 5* warmer overnight.

Here is a link that might be useful: Winter Cover

bulldinkie: Can you fix tarp on your pipe structure? But, if you only cover part of the pond, it will still freeze, right?

Mike: Thanks for the info about how to set up the air pump and fix the airstone. I will post some of my cover pictures.

woeisme: Thanks for the link! You made some cover there! Wish the pictures are larger though. I am setting a very low profile cover for my veggie bed.

Yes, I didnt mean to prevent freeze,I use a tank water floating heater keeps ice open good.I meant for them to hide because I have a heron.Once you take out all floating plants you can see the fish.

I am in zone 5a, only have a 4x7 ft pond, 18 in deep. For years I kept 7 goldfish in there over winter, no heat, no air, none ever died. I had removed all leaves and most of the scum before winter. My cover is simple, 4 pieces of 2x4s, an old plastic basketball plate, covered with 2 old shower curtains, all kept in place with 20 or so bricks and stones. The water rarely had a complete ice cover, snow helped there too.
The last years though I brought 'our' goldfish into the basement and a 55 gal aquarium, because my grandson wants to see and feed them.

I have a 5x10 (1.5 deep) homemade pond. I'm low-tech (much to the dismay of Mrs. Oklahawg):

1. I run an extension cord from the back patio to the pond. I buried one in a PVC pipe but the lawn guy sliced it off and there isn't enough slack to splice.
2. I use a standard livestock tank heater in the pond. It kicks in at 40 degrees. Rarely do I have a problem.
3. I have a plastic prefab outdoor playhouse my daughter outgrew. I took a section of that and placed it over one corner of the pond, reconfiguring the rocks from the pond edge to weight down the plastic piece. Its 2 inches thick so it won't bow under pressure. It only covers about 2.5 square feet of pond, but that's enough for the fish to hide under - I put the heater nearby.

I rake out leaves any day its decent outside - sun and not too cold. Seems like there is always crap blowing into the pond!

Also, I add water from the hose if I get days in the high 40s or higher. The water is 70 degrees, or so, as it comes out of the faucet. Its easy enough to attach and detach the hose from the faucet - I do this early enough in the day to allow any drippage to dry in the faucet.

The fresh water always makes the fish happy.

My biggest fish loss occurs in late, late winter when the water starts to warm, the fish start to become active and the natural food in the pond starts to disappear. (I've not "fed" the fish in years.)

I wasnt trying to keep it from freezing,I use a floating heater,you dont need to thaw the whole pond just a small area for gases to escape,Im trying to keep the great heron out of my pond.

I live in northern Wisconsin where winter temps can hit -40F. and hover around or under zero for days on end. I have had koi in my 1000+ gal pond for 5 years without a death. As others on this forum, I use PVC with untreated plywood over it, then a tarp. The tarp is held down with rocks around the edge, but there is an opening by the filter.

The filter pump is unhooked and set to blow water up from the pond like a big bubbler. It is an external filter and would freeze solid, anyway. Also, there would be no way to clean an underwater filter. I have tried them and they plug up and become useless.

The snow piling up on the tarp acts as an insulation. The koi are under there in the dark, under 2-3 feet of snow, in unfiltered water, with a water temp usually at around +35 F. for the better part of four months. What a happy day when I can finally pull the tarp off and see the koi still motoring around and set up the pond again. The koi are just as happy!

I figured it's time to give an update about my pond cover.

Thanks to everybody's great ideas here, I made a plywood cover, covered it with heavy duty tarp, weighted down by some brick(See pictures). Underneath the cover, I have a de-icer and a double-outlet airpump with tubing and airstone attached. The plywood cover is holding up well. So far, it has survived:

1) Strong gusty wind

2) Close to 2-foot snow cumulation on top

3) An ice rain that lasted a whole day after the snow storm.

I did shovel the snow/ice off the cover after the ice rain froze over because I could see the frame bended a little bit.

During the whole time, the airpump kept a very seasonable size opening of the pond. There is also always enough openning between the cover and pond even when the snow storm almost burried everything.

I won't know about the condition of the fish until the snow melts away, but I am optimistic. Next year, I am comfortable enough to use just the air pump without the de-icer, it will save energy. Air pump uses 4W, the de-icer 200W.
{{gwi:235411}}

{{gwi:235412}}

{{gwi:235413}}

I also use the idea of PVC tubing suggested here on my veggie bed, the duc tape hold everything together quite well as you can see in the picture. This structure definitely can extend the growth season. However it sagged after the heavy snow:-(

{{gwi:235414}}

Hi,
I am from Europe-Serbia and I have winter problem with my pond too, here can also can be the -20C=-4F,
and I want to make a cover,
but I have one question,
Do you know what the difference in temperature inside the cover and the outer temperature ?
I know when a bit of sun to warm the inside cover but with no sun what is the difference inside the lid and out ?
and do you measured the water temperature at the bottom of the winter under cover ?
My pond have 1,5meters=59inches depth and have on bottom 4C=39.2F without cover, and outer air temperature is between 0 and -10C, but 4C=39.2F is too low for KOI and Gold fish and I want to accomplish more with a lid but I do not know how much it might be.

Thanks.

We have several goldfish in our pond. It freezes every winter and the fish are fine in the Spring. We usually have a bunch of leaves in the pond and it is hard to clean. So this year my husband covered the pond with a tarp. I hope the fish are ok. Has anyone done this with no air for the fish? My husband asked me what the difference is when it is covered in ice. I guess no difference. I guess we will find out how they are in the Spring.

I covered a small pond with visqueen laid over a wooden frame one winter to protect my tropical plants. It worked but I never did it again. My current pond is larger so it would be harder to do.

Is the tarp in contact with the water? I’d think you’d want some air space between the two. Will any sunlight penetrate the tarp into the pond?