Re: NANFA-- Temps- long - w/observations of last year

R. W. Wolff (
Sat, 25 Oct 2003 10:42:06 -0500

I have a good deal of current in my pond. Generally during stable weather
the temps is nearly the same top to bottom ( shore to 6 foot). Sun can
easily warm the shallows ( down to 6 inches) to well above 90 even on cool
days. In the summer, surface temps are around air temps, depending on time
of day, wind and sun. Going deeper it gets cooler. Some time in late summer
I had surface temps in the low 80's, most of the depth was in the low 70's,
and the bottom was in the high 60's. If the low was 50, the surface could
get to the low 70's, and it would increase the layer of cold water. On hot
sunny days, the trend was reversed, thinning the cold slug on the bottom of
the deep holes. Come fall, everything changes. More cloudy days, cold
nights, and lots of wind are main factors. Water in the deep is often warmer
than the mid depths, and sometimes the surface depending on the factors I
explained. In winter, everything calms down. The surface is ice, from the
ice to the bottom temps can range from freezeing of course, to as low as 39
degrees. However, last winter was so terrible, for a few months water temps
were near freezeing to the bottom of the pond! Regardless of what people in
their warm homes thought of last winters snowless no record low temps (
plenty of record low highs!) , it was the worst winter possible for things
living in the pond. I lost numerous plants native to the area. During a
normal winter, the deep holes get recharged with sun, and some warmer days,
and keep some water in the forties. One thing working against me last
winter was increased flow. This winter I have to shut down one of the two
pumps. Helping me from a severe loss was green houses over parts of the pond
made from pvc tubeing and clear plastic sheeting. Even on the coldest days,
these "lame" green houses could warm to the mid 50s with some good sun, and
really warm the water in those areas. They protected plants that died
outside the green houses, even though the entire systems water circulated.

This late fall I plan to have green house like this constructed over the
entire pond for insurance against another winter like last. I have pictures
I could post, but don't know if that function exists yet ( thought I heard
of it???) on the NANFA web site, of the green house last year. Construction
is simple, and quick. Initial planning takes some time, but once you get
going it is no harder than putting up the leaf netting. This along with
light bulb heaters and back up stock tank heaters, hopefully will really
keep me going if we get another doozy. There is some maintenance involved
with these structure througout winter. Snow needs to be brushed off in a
timely manner. Also, condensation can build up thick snow like deposits on
the inside of the plastic. This works for you at night, adding insulation.
On warm sunny days this usually drops off on its own. On cold sunny days, it
has to be tapped off. Useing a yard stick, and lightly rapping on the
plastic the frost will drop off and be added back to the ponds water, rather
than disappearring into the night sky.

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