Do ponds get O2 in winter after the waterfall's shut down?

[Mayank]

So it's November! Except for today the weather is actually pretty mild for the next 10 days and next weekend is high sixties and low around 50 which is pretty warm for November I think. All my questions are simply to determine what is best for the health of my fish. That's my main focus.
Today we are going to move the diffuser to the middle level (18 in) in our pond which is shallower so that the deep level (42 in) can remain undisturbed for the next few months. We are also going to remove most of the annuals today even though they're still kinda green.
I am assuming that our diffuser will be enough for winter because cold water stores more oxygen but what about so many other ponds that don't have a diffuser. How do they manage to have enough oxygen?
Also, what about filtration? Once our pumps are turned off there will be no filtration for months. Thanks why I'm planning to leave my pumps on till wintry weather actually hits. Is that ok? I've heard of some people keeping their waterfalls etc going all winter. How do they do that? Is that even desirable?

 

[Mayank]

Here's what it looks like today.

 

[mrsclem]

Love your cover! I have already pulled the aerator for the winter. Lilies pulled and moved to new pond. I run my filters and pumps until I start to get at least 50% of pond covered with ice. As the fish are not as active, they are fine. I use low wattage heaters to protect light and camera cables so they are not damaged by ice and Pond Breathers to keep a hole open for gas exchange. Last year was mild so we ran everything all winter except my bogs.

 

[Jhn]

Leave my water running all winter, as well. As mrsclem said fish are less active so the O2 requirements aren’t as high. I toss pond breathers unplugged in my ponds more as a back up, but as long as ice can’t divert water out of the pond I would just leave stuff running, no downside to it...also pumps need to be in the pond where it can’t freeze. I wouldn’t try it with an external pump.

 

[brokensword]

comments inline, below;

So it's November! Except for today the weather is actually pretty mild for the next 10 days and next weekend is high sixties and low around 50 which is pretty warm for November I think. All my questions are simply to determine what is best for the health of my fish. That's my main focus.
Today we are going to move the diffuser to the middle level (18 in) in our pond which is shallower so that the deep level (42 in) can remain undisturbed for the next few months.

Unless your pond is more than 5' deep, there won't be any noticeable thermocline. Still, according to anecdedotes on PondBass forum, it's best to raise the aerator to near the surface. I'd go to the 12" level.

We are also going to remove most of the annuals today even though they're still kinda green.
I am assuming that our diffuser will be enough for winter because cold water stores more oxygen

Realize that it itsn't the bubbles from your aerator passing through the water column that creates necessary oxygen for your fish but rather, surface aggitation.

but what about so many other ponds that don't have a diffuser. How do they manage to have enough oxygen?

Lakes and natural ponds depend on large surface area and wind, plus some sort of break in the weather to allow the ice to thaw. You can have fish kills because the ice remained too long and toxic gasses from rotting vegetation below couldn't escape. Also, with ice/snow cover, algae was limited to how much oxygen they could emit. That's why with ponds it's better to have large surface area and depth is less important re aeration.

Also, what about filtration? Once our pumps are turned off there will be no filtration for months. Thanks why I'm planning to leave my pumps on till wintry weather actually hits. Is that ok? I've heard of some people keeping their waterfalls etc going all winter. How do they do that? Is that even desirable?

Your fish won't need filtratiion if they're just hanging around in a torpor. The bacteria will die off/go dormant at lower temps, too. And since bacteria colonies lag fish activity is why spring is the season your fish are most susceptible to health issues. I used to just use an aerator to keep a hole open to let the toxic gases out, then went to pond breathers. Now, since I have koi, I've let the falls run and I cover with plastic sheeting, which reduces evaporation and helps keep the water warmer. Having your falls run constantly is only an issue if you fear ice dams diverting your water out of the pond. It isn't necessary to have the falls running though and you can just have the output of your pump pushing the surface water alone.

 

[Lisak1]

What a pretty pond!

How many fish do you have, what kind and how many gallons is your pond? I think goldfish are better able to handle a complete pond shut down in winter than big koi, especially if you're already near your limits with the number of fish you have. Keeping the pond running is one option that some ponders choose. A lot depends on the construction of your pond and waterfall, whether it can handle some ice without diverting water out of the pond.

 

[GBBUDD]

Here in CT I let the pond run untill x mass . We never have long periods of freeze untill January. Like Lisa asked i have some large koi and getting bigger every year. I run a air pump that goes to my bog and to a 12 inch deep shelf in the pond. Now I have heard an air pump can chill the water too much but my pump is in the walkout basement stairwell so its not super chilled but its not warm either. The air does add o2 by surface agitation that stops water of C02 and keeps the surface open for gases to escape. And the bog gets air to keep the water moving and airated

 

[Mayank]

Here in CT I let the pond run untill x mass . We never have long periods of freeze untill January. Like Lisa asked i have some large koi and getting bigger every year. I run a air pump that goes to my bog and to a 12 inch deep shelf in the pond. Now I have heard an air pump can chill the water too much but my pump is in the walkout basement stairwell so its not super chilled but its not warm either. The air does add o2 by surface agitation that stops water of C02 and keeps the surface open for gases to escape. And the bog gets air to keep the water moving and airated

Do you think my aerator could cool the water too much. I mean when temps drop into teens or below will that super cold air going through the water column cause super chilling. I mean if its still water and not ice and if I add a deicer will it be an issue?

 

[Mayank]

The aerator is in that blue box. Should it be more protected somehow? How do I do that?

 

[Mayank]

What a pretty pond!

How many fish do you have, what kind and how many gallons is your pond? I think goldfish are better able to handle a complete pond shut down in winter than big koi, especially if you're already near your limits with the number of fish you have. Keeping the pond running is one option that some ponders choose. A lot depends on the construction of your pond and waterfall, whether it can handle some ice without diverting water out of the pond.

Sorry for the late response. Its been kinda wild at work esp with Covid etc. We have 5 goldfish/comets (6-8 inch) and one larger koi (about a foot) and six smaller butterfly koi (six inches). So 12 total. I'm thinking this is too much but of course we didn't know at the time and hadn't heard of this forum and went with the pond shop kid's recommendation of an inch of fish per 10 gallons. We have 1800 to 2000 gallons but we took 1700 for calculation and that gave us 14 one-foot fish so we thought we're cool. Halfway through summer I kinda panicked when I read more on this forum and our ammonia levels kinda rose so I bought an extra pump that we through in the deep and a filtration unit (pond max 3500 or something like that) so that we would have double the filtration. So far it seems to have worked and the fish are OK.

Just freaking out now about the aeration supercooling the pond water when the mercury really dips....

 

[Tula]

I run an aerator year round. In the winter I run a smaller aerator and suspend the air stones about 10 inches into the water. I have older, large koi and believe their O2 requirements are greater than gold fish.

 

[Mayank]

I run an aerator year round. In the winter I run a smaller aerator and suspend the air stones about 10 inches into the water. I have older, large koi and believe their O2 requirements are greater than gold fish.

Good to know. What is a smaller aerator? Mine seems too much doesn't it from the pic? What are air stones? Those blue things? I am assuming you connect the blue air stones to your aerator meaning that is where the air comes out?

 

[GBBUDD]

Yes aerators can chill the water. Like I said before mine is in a protected area that is always just a little warmer then it is outside.. I have larger koi as well and I do not trust a heating element to keep o2 levels up for them . And like previously mentioned its in the shallow end of the pond

 

[Mayank]

Yes aerators can chill the water. Like I said before mine is in a protected area that is always just a little warmer then it is outside.. I have larger koi as well and I do not trust a heating element to keep o2 levels up for them . And like previously mentioned its in the shallow end of the pond

I guess I do not have any protected area to keep the air pump. Should I just turn the aerator off when it gets super cold then and just use a deicer to keep a hole in the ice?

 

[Tula]

It should be fine under the Rubbermaid tub, place a rock on top of it to keep it from blowing over and rest a bottom edge on another rock for air circulation.

In the summer I run a 40 LPM aerator and in the winter a 20 LPM