New pond owner. I need help.

[MitchM]

I'm not a cold weather guy, but...

You should have stopped yourself there...

.

 

[carolinaguy]

You should have stopped yourself there...

.

Because?

 

[MitchM]

The op hasn't provided us with any more information, so we're really just speculating at this point as to the cause of her fish deaths.

Because?

Because-
-Whether or not there is an air gap between the ice and water is irrelevant If the air gap is sealed off from the outside air. Plus you can't monitor any air gap . The pond water needs exposure to air above the ice. Active exposure is best (moving water)
-Koi can be fine down to 32F. People also need to take into account the accuracy of the temperature probe being used. Accuracy of a temperature probe can vary +/- 0.5 and 2 degrees Fahrenheit. A small distinction, but people get too hung up over water temperature.
-A floating trough style heater will have absolutely no effect on the water temperature of an outdoor pond. Outdoor pond heat loss is far too great.

 

[carolinaguy]

The op hasn't provided us with any more information, so we're really just speculating at this point as to the cause of her fish deaths.



Because-
-Whether or not there is an air gap between the ice and water is irrelevant If the air gap is sealed off from the outside air. Plus you can't monitor any air gap . The pond water needs exposure to air above the ice. Active exposure is best (moving water)
-Koi can be fine down to 32F. People also need to take into account the accuracy of the temperature probe being used. Accuracy of a temperature probe can vary +/- 0.5 and 2 degrees Fahrenheit. A small distinction, but people get too hung up over water temperature.
-A floating trough style heater will have absolutely no effect on the water temperature of an outdoor pond. Outdoor pond heat loss is far too great.

Good answer. Top moving water is absolutely the best idea. That is why a design that valves both bottom drains and the skimmer permits the owner to shut off bottom drains and create flow across the pond surface. I also valve the waterfall system and run sidewall ports that drive water across the surface in the winter. The bottom water stays warmer and air stones create a vertical flow that keeps ottom water oxygenated. Now that said northern ponds in Michigan for example are probably a different animal outside my experience, but if your outside air temperature remains above about 30 degrees on average during the day, then top flow works just fine to protect the school.

 

[Lisak1]

but if your outside air temperature remains above about 30 degrees on average during the day,

A temperature "above about on average" is quite a range of possibility.

 

[carolinaguy]

A temperature "above about on average" is quite a range of possibility.

Not really. A 31 degree average over daylight hours means the temperature varies between 28 or 29 in the morning and maybe 34 or 35 at the high. Perfect for dormant fish to survive the winter without the fear of an ice cap. As mark twain said "everyone talks about the weather but no one does anything about it"

 

[Lisak1]

haha! I understand the concept of an average... I'm just saying there were a few too many modifiers to draw any real conclusions.

 

[MitchM]

Good answer. Top moving water is absolutely the best idea. That is why a design that valves both bottom drains and the skimmer permits the owner to shut off bottom drains and create flow across the pond surface. I also valve the waterfall system and run sidewall ports that drive water across the surface in the winter. The bottom water stays warmer and air stones create a vertical flow that keeps ottom water oxygenated. Now that said northern ponds in Michigan for example are probably a different animal outside my experience, but if your outside air temperature remains above about 30 degrees on average during the day, then top flow works just fine to protect the school.

FWIW, if you have any ice cover plus water circulation, your pond will have zero difference in temperature between the top and bottom. The entire water body will be about 32.5F. I have sensors at the 2 foot and 5 foot level and have seen the difference even a little circulation can make.
My pond is frozen over for 6 months of the year, so elaborate plumbing systems like you mentioned are of no use to me. They do sound fun though.

.

 

[carolinaguy]

FWIW, if you have any ice cover plus water circulation, your pond will have zero difference in temperature between the top and bottom. The entire water body will be about 32.5F. I have sensors at the 2 foot and 5 foot level and have seen the difference even a little circulation can make.
My pond is frozen over for 6 months of the year, so elaborate plumbing systems like you mentioned are of no use to me. They do sound fun though.

.

I stand corrected.

 

[cas]

I have sensors at the 2 foot and 5 foot level and have seen the difference even a little circulation can make.

Question Mitch - so even if the circulation takes place in the top 12", the bottom water temp is also affected?

 

[MitchM]

Question Mitch - so even if the circulation takes place in the top 12", the bottom water temp is also affected?

I don't know how one would circulate only the top 12".
If you used a small pump and aimed the outlet vertically along the surface of the pond the current would continue until it hit the opposite wall and then be forced downward to return back to the pump inlet.
As the water current ran along the bottom of the ice, the ice would be eroded away and additionally cool the water.

The only current pattern I have not noticed a complete equalization of the water temperature is with a pond breather that uses vertical water circulation. Even with a pond breather, the lowest level water temperature does cool down a bit.

 

[cas]

I don't know how one would circulate only the top 12".

I was thinking of an air stone down 12" in the water and wondered if it would cool the water three feet down.

 

[MitchM]

I was thinking of an air stone down 12" in the water and wondered if it would cool the water three feet down.

I think that would create sufficient circulation to equalize your water temperature throughout the pond.

 

[crystal r]

Welcome!
What is the size of your pond? Length, width, depth.
Please describe the filtration and water circulation setup.
How old is the pond?
You did not kill the koi by putting in a heater.
Do you have any ice cover? If so, how much?
What part of the country do you live in?

Pictures are always helpful.

.

 

[crystal r]

It is a heater like you would put in a water trough. We have a friend that has Koi and that's what she uses.

I just purchased an aerator and will be turning the fountain back on now that it is staying above freezing.