Where ice is a problem -- is it best to COVER your pond vs letting it be covered with ice?

[Mmathis]

I just answered another member thread and now I wonder..... I don't have to worry about ice here, but reading everyone elses stories [and reading on different forums] brings up this question regarding how folks handle cold winters with ice.

So....

Please explain about COVERING the pond vs letting nature take its course (IOW, ice formation). Are there advantages of one method over the other? From what I read, both methods can result in losing fish, sooo.... Just curious.

(Just my 2 cents [oh, didn't there used to be a key for "cents?"], but it seems like a natural covering of ice WITH a hole for gas exchange would be better. It just seems like a cover, even with aeration, would inhibit gas exchange.)

 

[MitchM]

I think in milder climates with smaller ponds, there would be some merit in a cover. A cover on a small pond would lessen the amount of ice that forms by protecting the pond from the wind and still be easy to remove.
In my case, my pond is 30 feet wide and our temperatures get down to -40. That's too big to cover and uncover easily plus would not be able to withstand the snow load.
If a structure that size collapses, you could have a real disaster on your hands. Broken wood from the structure could penetrate the liner and if the plastic freezes on top of the ice, you can forget about any gas exchange until things thaw out.

 

[callingcolleen1]

Covering the pond is NOT a good idea, I tried that 20 years ago and came to the concluson that mold runs wild and you can get mold and fungus everywhere on your pond, liner, fish, ect. The ice is the best cover because the sun can still shine thew and burn up the mold and fungus. After 23 years of wintering pond I have tried just about everything, and the best way is to have a winter pump and good filter and a heater too. Keep water running and ice will melt quick. Mitch if you still have ice, I would bring the water level up over the ice and get a pump working, then the ice would melt very quick.

 

[MitchM]

... Mitch if you still have ice, I would bring the water level up over the ice and get a pump working, then the ice would melt very quick.

I still have ice, Colleen. 10 inches of it. Did you not see my year to year comparison pictures in my Pond in the Foothills thread?
I don't have any tool that would help me get a pump hose through that thick of ice. If I did, the water would only flow over the sides of the pond.

.

 

[MitchM]

You could reduce the potential for mould by having a small vent at each end of the pond cover. Don't try to make it air tight.

 

[dieselplower]

My post is based on 2 Winters of personal experience as well as a good amount of reading on this and other forums. One thing I can tell you is that people with $10,000 Koi are not even leaving them outside at all. Way too risky. That or they build fancy covers and heat the water. It is not a good idea to have a cover and keep the water in the 40 to 55 degree range. This is a range where the fish are not in their hibernation like state, nor are they fully active. So they are putting off a good amount of ammonia and they also want to eat. Problem with this is that there is a good chance the bacteria that process ammonia and nitrate are functioning at less than 10% of their full capacity. So there is a danger of running into high levels of toxic ammonia and nitrite in the pond. You either want the pond iced over with a small hole and the water to be in the mid 30 range, or you want to keep it at 60 (just a rough estimate) or higher.

 

[callingcolleen1]

My two biggest koi are 22 years old and doing very well, they have been outside in the coldest winters here in Canada for their whole life of 22 years and they are very alive and well. The trouble is people are lead to believe that a bubbler will be fine for big koi all winter, and wintering ponds can be difficult for many people. One small hole in the ice may not be enough as gases can still get trapped, but running water will carry deadly gases away and out of pond. I have seen many people here in Medicine Hat with ponds much bigger than mine, and they choose a bubbler and heater, and still their fish suffered horribly under the thick ice and died. If you are planning to winter your big koi you will need a big filter that is underwater, cause they should not freeze. I set up my ponds and buildt them with winter in mind. The three ponds all flow together just fine all winter, and I can get away with just one heater for all three connecting ponds. I know very well how ice behaves and how best to winter my pond, and I should know after 23 Canadian winters, exactly what to expect.
If you are not sure how your pond will winter, try with a few cheap goldfish and see how your pond winters, you will learn from your mistakes, as we all have, and after a while you too will know what to expect with your pond.

 

[callingcolleen1]

I also keep the biggest koi in the top pond where the water is at a constant level, no matter how much ice forms, the two top ponds will always have three feet of water under the ice, as the top ponds are pumped to max and free flow down the water ways. I only keep small goldfish in bottom pond as that pond freezes very hard because the water is NOT at the same level all the time like the top two ponds. I had over one foot of ice in the bottom pond as that pond freezes very hard and then there is much less actual water under the ice in that pond. The freshest water is in the top two ponds and so I keep the largest fish and biggest koi in the top ponds, as larger fish require more oxygen than small fish do.

 

[callingcolleen1]

Mitch I will go look at your thread, I was busy in yard this week and I can see you having a ton of ice, cause it was indeed a very long and very cold winter. I have not had a foot of ice in my bottom pond for years. I imagine that the river here will have large ice chunks comming down this year too.

 

[Mmathis]

Well, and I wasn't taking into consideration the thickness of the ice on any given pond, but good point, MitchM! My pond is roughly 17'x11' and it's a pain just to get a net cover up to keep leaves out.

So, thickness of ice on an uncovered pond as well as depth and weight of snow on a covered one. More food for thought, as well as circulation....

 

[Sunshine]

I often wondered about the humidity that would come with a covered pond. I was going to do it a few years back when we built the arbor over it. That would of made a perfect structure to do it. But, after thinking about the whole contained gases it would have, decided against it.

 

[callingcolleen1]

One other little note too, the fish you buy from pet stores are not very hardy. Some of them are very small but they are not actual babies, their growth has been stunted and small actual baby goldfish should be back colored for the first year or so. My small black baby goldfish in bottom pond are bigger than the small feeder goldfish in pet store. Also three yesrs ago when the bad big blue heron came and ate the small goldfish in bottom pond, I went to pet store and bought feeder goldfish to replace the ones that the heron ate. Those small feeder goldfish were very weak and not hardy so many died that following winter. I was just looking at my fat baby goldifsh that were born in my pond last summer, and they are still nice and fat and healthy, as the fish that are born in pond will be much more winter hardy too.
So if some of your fish that your got from pet store do not survive winter, it could be that they were too weak to begin with....

 

[Sunshine]

My very first fish was a feeder fish. My son came over one day and threw it in my uninhabited preform pond. He said it got too big for his Oscar to eat. He lived a very happy long safe life.

 

[addy1]

I have two 4-5 inch comets, in a small uncleaned preform, pretty darn mucked up, full of tads and a frog or two. Did not have a clue they were there until just recently. That little preform, is around 18 inches deep 2x3 feet sort of, I am sure it froze up this winter. No air etc. Those little suckers did great. It is the preform I am going to yank and replace with a liner, so ignored it in the fall.

 

[sissy]

stale air just like when you close up a room and allow no fresh air mold grows and it gets musty .