Minnesota pond winterization

[MattC]

Yes, I know I'm WAY early, but I got to thinking about it so I figured I'd ask.

I built an 8'x11' pond with waterfall this spring. It has 3 tiers to it. 12" deep along one end and side, a 20" deep shelf, and one end is 30" + deep. The walls are lined with boulders with gravel filling the voids and covering the horizontal surfaces. I have an aerator in the pond that I run a few hours at night and a few hours during the day off of a timer. I have a Helix brand skimmer, waterfall bio-filter, and external pump that is located 15' away in my shed.
I treat the pond with beneficial bacteria and barley straw extract according to the packaging.

I am going to over winter my two Koi in a stock tank in my garage. I don't think that my pond is deep enough to keep them out there year round.

At first I was thinking of removing the pump and storing it inside the house and draining the pond low enough to keep the water out of the skimmer. That way I can blow out the lines to keep them from freezing and damaging the pipes, waterfall filter and skimmer. I'd run the aerator all the time to try to keep a hole in the ice and dose the pond with cold weather beneficial bacteria.
My thinking was, even though I'm not keeping my Koi in there, I might as well keep most of the biofilm that's growing on my pond walls alive.

But I wonder if that's even worth the hassle?
I figure I'd probably drain the pond completely in the spring to clean any leafs and gunk out of the bottom and fill it back up.

Is it even worth trying to "save" the bio-film growing on the walls? Should I just drain it completely in the fall, clean it out in the spring, and fill it up?

What does everyone else do with their ponds when they over winter their fish out of the pond in the frozen north?

Thanks!

 

[sissy]

I live in VA but came from NJ but never had the problem up there ,but here i use a pond heater to keep a hole open .I know we have ponders in colder climates and hope one of them can help you

 

[Lisak1]

Your pond is deep enough for your koi to stay put for winter. If you can keep your pump running, that's even better. We are in far northern Illinois so our winters are similar. I've seen lots of ponds in our area that are no more than 2 feet deep and successfully overwinter koi year after year.

Personally I think it's way more stressful for koi to be moving twice a year and essentially into a "new" pond every spring.

 

[Lisak1]

We'd love to see pictures of your new pond if you haven't already posted them!

Oops! Never mind! I see them! Pretty pond!

 

[addy1]

A ponder up in Canada uses a pond breather over winter, his pond freezes deep.

I use one in my pond over the winter, no fish deaths. I turn everything off, I have a external pump and a huge bog as my ponds filter. The two items do not lead to leaving it running over winter.

 

[MitchM]

Yes, I use a couple of pond breathers, but with your pond, MattC, it depends on how large of an area the 30" deep space is.
It's always better to keep a biofilm going and don't add extras like winter bacteria or barley.
You know your plumbing setup best, so do what you need to do to protect it from freezing damage.

 

[Meyer Jordan]

It would take more than the environmental extremes of a Minnesota winter to seriously impair established biofilm.
As long as it is not allowed to dry out for several hours, the biofilm will remain secure. Bacterial activity will, of course, decrease as temperatures drop, but it only completely ceases at 0C/32F.
Adding cold water bacteria is a waste of money if there will be no fish in the pond.

 

[Tula]

I agree that you should be able to over winter your koi in the pond, provided you make sure they have adequate O2. When my koi were smaller, I didn't worry as much about O2, but as they've grown, it's a concern.

 

[MattC]

Thanks for the responses!
I went out and measured the 30" deep area. its 5' x 6'. I couldn't really go any deeper or make the pond bigger otherwise it would be considered a "pool" and I'd have to fence my yard in.

I don't want to run the pump during the winter because it would be easy for the waterfall / stream to freeze in spots and cause a leak. I also don't want to run the risk of freezing water to damage my filter, skimmer or plumbing.
By the time I lower the water level to keep water out of the skimmer the deepest part of the pond will be 24" max.

The handful of people I've talked to locally said it should be at least 3' deep to safely overwinter koi in a pond and that 4' is better.
I really don't want to risk killing my fish so I'm leaning towards wintering them in the garage.
I guess I just need to figure out of its worth keeping the pond half full and running the aerator to keep half of the biofilm alive through the winter.

 

[Lisak1]

You don't have to run your pump to keep your fish in your pond. Just drop a de-icer in to keep a hole in the ice. There are lots of folks who will tell you that fish need deeper water to over winter outdoors, but there are just as many who have experience that tells them otherwise.

Totally your choice of course - just want to share that there are options that don't involve removing the fish from the pond. Good luck with your planning!

 

[cas]

Here is a thread about using a pond breather during the winter. A lot of good information.

https://www.gardenpondforum.com/threads/pond-breather.15976/

I don't drain the water from my skimmer in the winter and haven't had any problems.

 

[addy1]

My skimmer is a external pool skimmer. I just put bubble wrap into a plastic bag, stuff it into the skimmer replacing the water with bubble wrap. We have frozen down 18 inches, but that is unusual for us.
In the spring pull it back out all is good.

 

[pecan]

Great advice given, ill add, please don't drain and refill completely once a year. If you do that your pond will never get established. In my opinion it takes about 3 years for a pond to find its natural balance.

Most I have ever drained in 5 years is about 30%-50% of the water for a major water change and it was refilled immediately.

 

[MattC]

Thanks again for all the info!
I read through the pond breather thread, but I'm still on the fence about leaving my koi in the pond through the winter. Seems everyone in that thread either lived in an area that didn't get too cold and only got a few inches of ice, or they had 5' deep ponds.

I don't think filling my skimmer with bubble wrap would work in my case. I have a pipe going from my skimmer to the pump that's in my shed. The bubble wrap may keep my skimmer from being damaged but it wont keep the water in the pipe from freezing.
That's why I think I need to drain my pond to 24" deep. That way water stays out of the skimmer and I can blow all of the water out of my plumbing.

I think I'm going to stick to my original plan, but skip aerating it. I'll drain it down just enough to keep water out of the skimmer, drain the waterfall filter, blow out the lines and keep my koi in the garage.