ideal pond depth for hobbyist pond?

[jnorth]

First of all Luke I'm talking about ponds deeper then 6 feet. I agree that 6 feet would be optimal (or 6.4 feet/2m). However when you go say 8 feet or 10 feet and shut down your pump for winter you will get thermal layers. The warmer water will be found at the bottom as the warmer earth below the frost line will keep it at a higher temperature. So now say you go out to your pond in the middle of winter and decide you want to get rid of some ice or because you read on the internet to run your pump all winter. Your pump that turns your pond over once an hour has now disrupted that layer and caused a significant temperature drop at the bottom where all the koi are. It makes sense to me that dropping water from say 39 to 36/37 in an hour would not be a good idea.

If the pond were heated then the pump would be running and I doubt you would have thermal layer problems.

[luke frisbee]

thermocline? or thermal layers? you were not speaking of a thermocline...just using words that you don't know... not good


def from answers:

ther·mo·cline (thûr'mə-klīn')
n.
A layer in a large body of water, such as a lake, that sharply separates regions differing in temperature, so that the temperature gradient across the layer is abrupt.

[jnorth]

A thermocline is a LAYER of water thats a different temperature from another LAYER of water. I wonder why I might have said thermal layer? I'll try not to be so ignorant the next time.

[kiky]

Thanks Luke,

By the way, do you have a photo of your 'pigeon-breasted' koi. I'd appreciate if could post it here. I have not known such koi before.

[luke frisbee]

Quote: Originally Posted by jnorth A thermocline is a LAYER of water thats a different temperature from another LAYER of water. I wonder why I might have said thermal layer? I'll try not to be so ignorant the next time.

ya still don't have it right..but keep posting, someone else might have learned what I said

[luke frisbee]

pigeon breasted koi....people say this happens from having a Shallow pond. i disagree..one day I will find it ..or photograph it (by accident) again

[PapaBear]

If you just want a nice, healthy home for your pets a 4'-6' depth is great. If your purpose is to raise massive show stoppers deeper definitely works. At the OKC Koi show my wife and I were admiring Dan and Genes GC Kohaku and MASSIVE Yamabuki (ok, my bride was drooling all over the yamabuki ). I commented on the outstanding bodies of their Koi and Gene replied that their pond is 10' deep with heavy currents. A perfect environment for a body builder.
As to thermal layering/thermoclines, they do exist to varying degrees in different settings. ALL liquids and gases tend to establish temperature layers which change with environmental conditions. Go for a swim in a local lake during the heat of summer and you'll have a warm surface layer at the chest, a warm bottom layer at your feet, and a cool current flowing across your midsection. The cool currents across even a 1000 acre lake will maintain an even depth from end to end because the water laminates itself.
If we use pumps to create top to bottom circulation we disrupt the natural layering and thermoclines no longer are a factor. JNorth is right about northern climes needing added depth. Where I used to live (Central Wyoming, Rattlesnake Mountain Range) the frost line was 6' deep. To keep koi there I either would have needed to have a heater or a 12' deep pond.

[luke frisbee]

papa bear,
Amazing, I can't offer a rebuttal. JG would be proud.

[luke frisbee]

but this tends to support your position...but only at a very cold and specific temperature where the water would be almost frozen at the surface, and below 62 degrees below that and then around 39.16 degrees at the bottom.
This is of course preposterous but does occasionally happen resulting in some tremendous and quite unusual fish kills.
But to give some understanding to your 'feeling the temperature".
A body cannot register temperatures...only the degree to which heat is being lost or gained....the often given example is when people play in th esnow without gloves and come in and put their hands under 50 degree tapwater they swear the water is HOT.
Anecdotal information is misleading.


Density of water calculated from formula in 68th CRC Handbook of Chemistry and Physics 1987–1988.

Density of water at 1 atm (101.325 kPa, 14.7 psi)
(little or no difference at 100 kPa) TemperatureDensityCelsiusFahrenheitkg/m³
32 °F 999.839523.98
39.16 °F 999.972015
59 °F 999.099616 2/3
62 °F 998.832220
68 °F 998.204125
77 °F 997.0449

as you can see water becomes more dense till it cools to 39.16F. At that point it becomes less dense as it starts to form crystals until the crystline network is near complete (ice).
But the middle water being cooler than the water above or below it....like I said, JG will be proud of you.

[Steve Nguyen]

maybe it's the heavy currents that provided a good body builder.

Steve

Quote: Originally Posted by PapaBear If you just want a nice, healthy home for your pets a 4'-6' depth is great. If your purpose is to raise massive show stoppers deeper definitely works. At the OKC Koi show my wife and I were admiring Dan and Genes GC Kohaku and MASSIVE Yamabuki (ok, my bride was drooling all over the yamabuki ). I commented on the outstanding bodies of their Koi and Gene replied that their pond is 10' deep with heavy currents. A perfect environment for a body builder. As to thermal layering/thermoclines, they do exist to varying degrees in different settings. ALL liquids and gases tend to establish temperature layers which change with environmental conditions. Go for a swim in a local lake during the heat of summer and you'll have a warm surface layer at the chest, a warm bottom layer at your feet, and a cool current flowing across your midsection. The cool currents across even a 1000 acre lake will maintain an even depth from end to end because the water laminates itself. If we use pumps to create top to bottom circulation we disrupt the natural layering and thermoclines no longer are a factor. JNorth is right about northern climes needing added depth. Where I used to live (Central Wyoming, Rattlesnake Mountain Range) the frost line was 6' deep. To keep koi there I either would have needed to have a heater or a 12' deep pond.