iN THE COLDER PARTS OF THE WORLD! WHAT TEMPERATURE ARE YOUR PONDS...

[Beniguy]

Pleasanton, CA
right now at 49, wish I could afford to heat.

[moikoi]

here in Sacto,Ca current outside temp is 50.7*

my current pond temp is 48.2* at 7 ft deep with waterfall running.

[Auntiesue]

Minnesota here!! Both ponds are frozen over with a layer of snow covering the entire surface, but I still see water movement from the air domes. We don't leave the fish outdoors. We just drop the water levels to protect the plumbing, float 1" pink house insulation on the surface and run the air domes all winter. So far this is working well and the pond is not frozen solid.

[RookieKoiGuy]

Whats the coldest water anyone has heard of koi living in?
I know some of you in the UK have some cold ponds...

Tom

[B.Scott]

Quote: Originally Posted by RookieKoiGuy Whats the coldest water anyone has heard of koi living in? I know some of you in the UK have some cold ponds... Tom

Tom substitute the word living with surviving. Sky-divers jump out of planes and still survive despite a chute that didn't open.

My personal feeling is that the watershed between living and surviving lies at 6°C (about 42°F for those still in the stone age) When temperatures hit this point I always notice a marked difference in koi behavior. They stop eating, hug the bottom and if you listen closely you might just hear them praying for warmth. I have special hi protein low lipid, sinking feed I use in the winter and the fish will still eat this readily (though in very small potions) at 7°C but at a degree lower things take a big turn for the worse. I do heat as is necessary to keep the water from going no lower than 7-8°C. The pond is covered and insulated to keep the cost within reason.

B.Scott

[KoiCop]

Water has several unique properties.

One of them is that while it has one temperature at which it freezes, it has another temperature at which it is densest: 39 degrees F.

So unless natural density stratification has been disturbed, that will be the temperature at the bottom of the pond as long as the temperature at the surface is at or below 39 degrees.

Unless the pond has been salted, of course. Since salt changes water's density, salting the pond will allow water temps at the bottom of the pond to drop below 39 degrees F. And that is not a good idea for fish enduring winter statis.

[B.Scott]

That said Don, the smallest amount of circulation will be enough to negate any hope of stratification. Filters pumping and air columns will pretty much make it impossible unless the pond is closer to a lake. On the other hand the water at the bottom will be subject to slight warming due to ground (water) and the difference between the earth and air.

B.Scott

[KoiCop]

Quote: Originally Posted by B.Scott That said Don, the smallest amount of circulation will be enough to negate any hope of stratification.

Agreed, Scotty, which is why I said "So unless natural density stratification has been disturbed . . ."

That's why folks who winter their koi under ice have to shut off their bottom drains, air diffusers, waterfalls, baki showers, etc. -- whereas skimmers, upper level returns and air stones just below the surface are still OK as long as the pipes don't freeze.