John Bachman wrote in
:

On Sat, 4 Oct 2003 08:04:43 -0500, "Tom La Bron"
wrote:

Superkitt,

Where is the second pump that you left running drawing its water from?
If it is at the deepest part of the pond you should position it in an
area where the water is shallower. The fish will congregate where the
water is deepest and you do not want to pulling the water from the
deepest part of your pond. You want to leave this area pretty much
undisturbed to allow the water to absorb heat from the ground. If you
are constantly pulling water from the deepest part of the pond you
will effect a cooling in that area making it harder for your fish to
sustain their body fat for the winter do to increased swimming
activity. It is a good idea to raise the pump off the bottom, but
leaving it in an area where there is less chance of it freezing in the
ice.

In any event, the whole idea is to leave the water in the deepest part
of the pond where the fish will stay undisturbed by water movement, so
it will absorb warmth from the ground.


Is that really true? I do not know the answer but what I do know
causes me to question your theory.

The reason I question it is that water has the very unusual
characteristic of being most dense at 39 degrees F. At temperaturs
above and below that it is less dense. Therefore, if there were no
flow induced by pumps, streams, etc. the water at the bottom of the
pond would be 39 degees F as long as the ground temperature was not
higher than that. If the ground temperature is higher then it does
not matter what you do.

If the ground temperature would get lower than 39 F, as it would in my
section of New Hampshire, then it seems to me that settling of the
dense 39 degree water into the deepest part actually keeps the ground
from freezing.

If that is so, then eventually the water will lose it's heat and
everything freezes. But, there are many days in which the air
temperature is above freezing. That warms the water to it's densest
point (39 F) and actually results in a warm flow from top to bottom.

I guess that now that I have written this and thought it through, you
are correct, the best policy is to leave the deep water alone. A
happy circumstance, being right even if for the wrong reason.

Does anyone see any flaws in the above. I would like to understand
the physics so I can operate my pond properly.

John





The small pump is only drawing water from top 6inchs of the pond, just
enough to splash a little bit of water on the surface, its not alot of
water.

The liner has been proped up in the middle to allow water and snow to
melt off and not to settle, because its black the sun should warm it up
to prevent snow from settling, but I can remove snow if it builds up.

I just wanted to know if it was alright if covering the pond is alright,
to help prevent the water from freezing up.
I have allowed air to get in, but in a way that its now blown in to
freezing the water and I will add an air stone when I buy one.

Joel.