Pumping under the ice

[DeepWater]

For the last 15 years of my 4 ft deep 2000 gal pond and 1200 GPH pump, I've ran it all winter. The waterfall, stream and pond all did fine through deep cold spells - except for some years 2 conditions:
- below 0 F for several days with no snow cover to insulate. Stream would slush up and ice buildup would mound ice until pond water level dropped to the 3 ft submerged pump. Same cold spells with snow cover would be fine.
- ground frozen and power outage lasting more than a blip. The pump tubing was 35' long and buried 12" deep. No more running until spring...

I remodeled it this year to somewhere between 7500-10000 gal garden pond, 5.5' deep. 3000 GPH pump that is submerged 18" deep and fed from 2 inputs on a PVC wye, each side with a 2" shut-off valve.
- 1 input fed from 18" deep
- 1 input fed from 5' deep

So far I run both inputs wide open. I of course plan to run the system all winter. No koi, but dozens of rosy red minnows and hundreds of dragonfly nymphs. Finally the question...

Do I want to tweak the shut-off valves either way before surface ice locks me out?
- Suck only warmer 5' water to keep gasses turning over?
- Suck only 18" water to let a thermocline setup and remain undisturbed?
- leave both wide open and let ice depth dictate source input flow rates?

 

[addy1]

I turn all off over winter and run just a pond breather. All the fish and critters do fine. I started using the pond breather after @MitchM posted about using it up in Canada. His pond is frozen for a long time. It uses 40 watts of electricity. My pump is external, my filter is a large bog, no way can it run even in our relatively warmer than you winters.

A friend here lost all his fish after running an aerator all winter, most likely super cooled the water i.e. disturbed it too much. I do know of others that run heaters and pumps all winter, @callingcolleen1 she is up in Canada.

 

[MitchM]

You've been running a pond for quite some time, so you have a pretty good idea what to expect, but I would err on the side of caution and shut off/drain any items that could be damaged from freezing.
Pond Breathers are a great way to provide your pond with gas exchange during periods of ice cover.
Your pond won't have any noticeable temperature differences between the top and bottom. I measure mine each year and the temperature difference is negligible. My pond is 5 feet deep and I get up to 2 feet of ice cover thickness. My ice cover lasts for 6 months.

 

[DeepWater]

I (and the birds and squirrels) enjoy the exposed waterfall in the icy days, especially during early and late winter - when often there are thawing periods. I'll continue running the pump this year, as an experiment. Even with significant ice buildup, there's enough surface area to lose a significant volume before any dry pumping would occur.

Pond ice over is roughly beginning of December to mid March, though we've had mid winter thaws where water is 100% open again.

And thanks MitchM for the water temp difference info - I guess it won't matter where the water is drawn from. I'll keep both valves open to continue as much under ice water movement as possible.

 

[peter hillman]

My pond is 5 feet deep and I get up to 2 feet of ice cover thickness. My ice cover lasts for 6 months.

That's what you call a pond? Hmm, 'ice garden'. Or my lil hockey rink..

 

[DeepWater]

OK this is not the remodeled pond, lol! But it's last year's ice rink created "on the other side of the mini fence" from the old pond. This fall the helpers that spread out the liner with me said I'm going to be making an ice rink More pics to come.

 

[snoozer]

Your little helpers are so cute.

 

[addy1]

OK this is not the remodeled pond, lol! But it's last year's ice rink created "on the other side of the mini fence" from the old pond. This fall the helpers that spread out the liner with me said I'm going to be making an ice rink More pics to come.

So neat! My dad went out every winter with the first good snow fall, stomped down the snow, and spent hours wetting it down. We would skate in our back yard around the dogwood tree until it melted. It was not smooth, but boy did we have fun.
Back then we had a lot more snow and colder winters in Maryland.

 

[DeepWater]

And then on the left side of that mini fence, the new pond is frozen over and is an even larger skating rink than last year's fake rink! The camera flash hides the cool aspect of glowing ice from the underwater lights.
The mini fence was removed this summer as part of the pond remodel. The waterfall is still running, it created a shell over itself. The ice seems to be 8 to 10 inches thick.

 

[DeepWater]

Pond is shoveled off and waiting for more ice skaters. Recent temps at and just above freezing have opened a small hole in the stream just below the waterfall. This was a bird paradise this afternoon, with a bathing hole back open! Juncos, multiple male and female cardinals, chickadees, finches, sparrows, bluejays, and crows. Usually see some nuthatches too.

 

[sissy]

Those aren't lights ,those are alien space ships with friendly Martians More fun than just saying they are lights .

 

[MitchM]

... Usually see some nuthatches too.
..

Nuthatches are crazy birds. They're the firsts one to grab peanuts from the feeder.
Their beaks are small! What are they going to do with a peanut?

 

[addy1]

I keep a very small pump running in the shallow end of the big pond. The output just breaking the surface. It keeps a nice hole of fresh water for the birds. They love it.

 

[DeepWater]

Temps are in the mid 40s today and it rained last night. The snowman collapsed

There is about 2 inches of water on top of the ice now. The upper bog is open again, as is a larger portion of the stream. Luckily the water flow is still under the ice, everything on top is motionless-except for the wind! Low of 20 tonight so hopefully it re-freezes smooth and solid.

 

[DeepWater]

The first blast of cold air made the ice thick enough that I was able to walk on it Dec 13. I guessed about 4 inches thick.

It really did freeze nice and clear all over. Pump still running, submerged about 18" down. The return flow stream is seen looping around to the left at the top of this pic.

The waterfall shelled over a couple weeks earlier and received some snow on it before the main pond froze.

This is the bog above the waterfall. Mostly froze over at this point. Birds still bathe in the ice cold water... I don't understand how they can do that!