George wrote:
Large ponds and lakes are a bit different because of the dilution factor,
and because there are usually inflow and outflow routes. If they have
inflow and outflow routes, then the pH can fluctuate during times of heavy
rainfall, but under normal conditions is relatively stable. Having said
that, large ponds and lakes in temperate zones tend to stratify and then
overturn with the changing seasons. Large ponds and lakes in sub-tropical
to tropical zones rarely overturn, and so remain stratified for long
periods of time, which causes a buildup of gases in the lower levels,
particularly of CO2 and H2S. Disturbing those layers (say due to an
earthquake or landslide/slip) can cause a release of large quantities of
built up gases all at once, which can potentially be a dangerous situation
for lifeforms living nearby. But for the size of the pond you are talking
about, I don't think that is much of a problem. There may be some minor
stratification, but if it is in a temperate zone, it will overturn during
the spring and fall, and naturally get rid of those gases.


That begets another question then.

For my pond (~100'x45'x25'deep) I am planning on drilling a water well
(the well is for more than just the pond). Summers here in Texas
typically mean ponds go dry, or at least drop their levels (not THIS
year...), so the well is to help keep the pond full.

I have been toying with the idea of having the pipe filling the pond be
at the BOTTOM of the pond, rather than what is typical around here (a
fountain which sprays the top). Would doing this help/hurt the
stratification that occurs during the hot weather?


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