Sarah-Sheepco has been my inspiration. If she can overwinter in MN, we all can! My impression was bigger was better for the above-ground tank so we don't have to bring stuff inside. Too much volume to freeze solid. It's not as cold here as it is where you are but I'm worried, too. We'll see how the 8 foot does. That's about 700 gal. The plants from the tub garden are in there for the winter and will come back out in the spring (I hope).
Vanessa

Thanks, and I'll admit watergal is/was MY inspiration.

I don't think you'll have a problem in z6, but consider having a source for running water and/or a small de-icer on hand in case you get a prolonged cold spell - something that might give you a couple inches of ice.

Cath, no help here. My sheep tanks are 60 to 200 gallons above-ground, but have tank heaters. My above ground ponds get drained. My 300ga pond is 2/3 in-ground, and is getting a styro foam partial cover, a tank heater, and a bubbler this winter.

S

I do know 1 guy that has an 8' diameter above-ground tank, but he moves his plants to the basement and drains it for the winter.

Sounds like work to me.....S

Thanks Vanessa and Sarah.
Sarah......your above ground ponds.......are those for watergardens? If so, what do you keep in them in the summers?

Cath, I should have said above-ground "tanks".

I have the 1 - 300ga partial buried pond, 1 - 275ga liner pond, and 1 - 120 ga above-ground galvanized tank, these are my water gardens. They have a 1/2 whiskey barrel skippy (for the liner pond) and a 60ga tank veggie/skippy filter (for the 300 tank). The other tanks are water tanks for the sheep, nothing but water and algae in them :) The only water garden I keep going over winter is the 300ga tank in-ground. I move all the hardy plants and the 10 fish into it, and the tropicals into the house.

Thanks Sarah,
I would love to have a larger above-ground pond, but I think it would be a big hassle to clean out every fall. And I'd probably end up displacing alot of frogs/tadpoles that thought they had a nice place to overwinter.
Guess what I need is a big pond in the ground! Thanks again.

That large of a tank is not going to freeze solid like the smaller tanks. If you keep the water bubbling at the surface you should be fine. You could always stack a row of straw bales around the outside of it to help insulate.

Thanks lefd,
We have so many power failures out here in the winter, I'm just afraid to count on electricity.

lefd, true for most; but, no offense, even aerators will freeze over somewhere :)

When my pond survived its 1st winter with a de-icer and an airstone I thought - huh, piece of cake! All plants and fish AOK! The second winter we had almost no snow cover for insulation, -0F for 18 days straight in February, and windchill below 0F for another 2 weeks after that. My de-icer froze over for 2 weeks, and while the bubbler kept running and the pond didn't freeze solid, I lost my eight 6" goldfish/comets, and had some plants die.

My pond is on the wind-swept prairie of west central MN. Spend some time outdoors in a blizzard here and you can understand why lots of early settlers gave up and headed back east.

I'm taking the advice I should have heeded earlier and putting a sheet of styrofoam, or plywood + mulch, over 3/4's of my pond this year, and a tank heater with the bubbler.

I guess it depends the environment in your own yard, but I wouldn't trust even a 500ga above-ground with running water not to freeze here in my conditions without a tank heater AND straw bales...probably plywood on top too.

S

(Darn, it's 'cause I named 3 of those new fish!)

"lefd, true for most; but, no offense, even aerators will freeze over somewhere :)"

True, but my advice was aimed at her Zone 5 temps, not colder environments. I only keep the water bubbling in my tanks and they don't freeze over completely. During the coldest of winter here they will freeze over to the bubbling water, usually melting by mid-day. The 100 gallon tanks are a different story. They will freeze solid, even with the water moving but the larger tanks with larger volume don't freeze quite as easily.

So what's this business about thermoclines? I have read that bubblers and aerators can cause the water to mix too much bringing colder water down to the bottom. Would that only matter in deeper ponds? Our tanks are only about 2 feet. I'm planning on a stock tank heater and possibly a partial cover but I have a bubbler I could use. Hadn't considered straw bales but I might just do that, too.

Yeah, that is one of those raging debates. Its mostly an issue with people who have fish. I don't worry about it much with having only plants. The trick is you don't want the water really churning at the surface, just a gentle bubbling. I stack bricks up and put the pump close to the surface of the water so its not pulling water from the bottom area of the tank.
If you use an actual stock tank heater, you may not need a bubbler at all. Some tank heaters warm them up pretty good.

My bubbler is pretty wimpy so I guess I didn't worry about mixing up the water, I'm just trying to aerate the water a bit. Mine's just a little aquarium air pump with 2 airstones on the end of the tubing. I do keep it up off the bottom about 6 or 8".

lefdO5, that's what I meant - about different zones and all, sorry if it came out wrong. (I WISH I lived where a bubbler would keep my pond open :)

No sweat! :) I know it must be really tough for ponders who live in the really hard cold zones. Zones 5 & 6 can usually limp along through winter with just a few interventions.:)
Here where I live the month of December and first part of January is our coldest part of winter. Once I get things through that period of time there isn't much to worry about anything freezing real hard.

magdaloonie, how cold does it get at night, and during the day at your coldest times? And do you ever get long periods below freezing? Just curious, 'cause we all know 'zones' are never what we really experience in our own back yards. For instance I wouldn't think you'd ever need straw bales, but I don't live there!

That's a great question Sheepco but this will only be my 5th winter here. Each one has been different and every year people say it's an unusual winter! The weather and climate maps are little help because we're so affected by our elevation being a couple thousand feet above what surrounds us. Going by the coldest one so far, it was in the low teens, even some single digits every night for 2 or 3 weeks and in the 20s during the day. I think that's truly unusual. The western regional climate center has historical data for the town and it says average low of 19, average high of 46 in January. It does warm up a great deal when the sun comes up, even in the deepest winter. I have also discovered that the nearest source of straw bales is about 80 miles away. I can get hay but that's pretty pricey. I think I'll hope for a "normal" winter. Vanessa

Its sounds like your winters are pretty close to mine. I'm also in the high desert. I think you'll be o.k. with the larger tank.

I would think so too.

If my family wasn't all here I think I'd move - I'm sure I could like 'high desert'.....

I'm feeling pretty good about MY tank (except for the teeny leak that developed on the side seam 2 days ago - yikes!)but I'm curious about Catherine's.

It's sounding to me, Catherine, that you might replace one of the ones you are already running the de-icer in with a larger tank, use the same amount of power but be able to over winter more stuff with less risk of a power failure wiping you out. Maybe move plants from the 100 gal into the bigger tank for the winter instead of bringing them inside.

Lefd05 & Sheepco - does that sound right?

And the high desert is a wonderful climate but I go through some serious moisturizer and carmex. Bet Lefd05 does too!
Vanessa

"And the high desert is a wonderful climate but I go through some serious moisturizer and carmex. Bet Lefd05 does too! "

LOL! Yes indeed! :) Burt's Bees and Kiss My Face products keep me going.:)