Safe Haven for Koi Carp in winter
Safe Haven for Koi Carp in winter
(OP)
Hi All,
In order to prevent our koi from experiencing dangerously low (less than 5 degC) temperatures in winter, I am thinking of creating a safe haven for them within the pond in our garden.
The idea would be to build a box out of insulated board (such as celotex), say 1m square with a height of 0.5m, with an an opening on one side large enough for the fish to enter and leave (say 0.2m diameter), which would be anchored near the bottom of the pond. The box would have an electrical aquarium type heater, with the thermostat set at 5 degC.
To ascertain whether or not this is feasible, I am looking for an equation to model this situation, which calculates steady state conductive heat loss from an isothermal body (in this case a disk of 0.2m diameter) at temperature T1, which is exposed on one side to a (semi-) infinite volume of water at temperature T2. Worst case would probably be T2 of 2 decC with T1 at 5 degC. For sake of simplicity, I would also assume that there is zero heat loss across the insulated walls of the box.
Would really appreciate if anyone could help with this.
Cheers
Big Vern, Leatherhead, Surrey, UK
In order to prevent our koi from experiencing dangerously low (less than 5 degC) temperatures in winter, I am thinking of creating a safe haven for them within the pond in our garden.
The idea would be to build a box out of insulated board (such as celotex), say 1m square with a height of 0.5m, with an an opening on one side large enough for the fish to enter and leave (say 0.2m diameter), which would be anchored near the bottom of the pond. The box would have an electrical aquarium type heater, with the thermostat set at 5 degC.
To ascertain whether or not this is feasible, I am looking for an equation to model this situation, which calculates steady state conductive heat loss from an isothermal body (in this case a disk of 0.2m diameter) at temperature T1, which is exposed on one side to a (semi-) infinite volume of water at temperature T2. Worst case would probably be T2 of 2 decC with T1 at 5 degC. For sake of simplicity, I would also assume that there is zero heat loss across the insulated walls of the box.
Would really appreciate if anyone could help with this.
Cheers
Big Vern, Leatherhead, Surrey, UK





RE: Safe Haven for Koi Carp in winter
When we lived in Indianapolis our neighbor had one end of his pond 3' deep.
The mud protected then fine.
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P.E. Metallurgy, Plymouth Tube
RE: Safe Haven for Koi Carp in winter
RE: Safe Haven for Koi Carp in winter
RE: Safe Haven for Koi Carp in winter
Use the whole pond as the thermal space and not just a box. The carp could avoid the box as a dark hazard. They could also run the oxygen way down if they actually did hang out in the box.
Keith Cress
kcress - http://www.flaminsystems.com
RE: Safe Haven for Koi Carp in winter
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Safe Haven for Koi Carp in winter
They provide some insulation and they allow some solar gain.
Floating that on the pond my do the trick.
And then if you still need to add heat it will help trap it better.
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P.E. Metallurgy, Plymouth Tube
RE: Safe Haven for Koi Carp in winter
https://www.youtube.com/watch?v=5NU0Mv_bKtU
8<)
RE: Safe Haven for Koi Carp in winter
RE: Safe Haven for Koi Carp in winter
RE: Safe Haven for Koi Carp in winter
Dan - Owner
http://www.Hi-TecDesigns.com
RE: Safe Haven for Koi Carp in winter
John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
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It's finding someone you can't live without
RE: Safe Haven for Koi Carp in winter
RE: Safe Haven for Koi Carp in winter
Yes, predators are a big issue, both birds and various critters.
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P.E. Metallurgy, Plymouth Tube
RE: Safe Haven for Koi Carp in winter
RE: Safe Haven for Koi Carp in winter
RE: Safe Haven for Koi Carp in winter
In terms of throwing a plastic sheet over the Heron netting, does your netting have a suitable pitch to it so that precipitation won't collect. Even with pitch any snow might be an issue. I'd also be a bit worried about wind unless you can anchor it really well.
If memory serves the water at the bottom of a cold pond will normally be at least 4°C because the peak density of water is at this temperature. So if your confined region can be kept on the bottom of the pond you're only looking to heat it a relatively small amount.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Safe Haven for Koi Carp in winter
I'm in central Indiana.
We have bubblers, and a trough heater, and have never had issues with our goldfish or koi.
On the subject of the catfish... we also have a large channel cat in there, and have never had a problem with him eating other fish...
I have always had catfish in my ponds. They may go after the babies, though, and get them before we even realize they're there.
David
Connect with me on LinkedIn. http://lnkd.in/fY7-QK
Quote: "If it ain't broke, I must not've fixed it good enough"
RE: Safe Haven for Koi Carp in winter
RE: Safe Haven for Koi Carp in winter
Bill
--------------------
"Why not the best?"
Jimmy Carter