This is just to add to what was said in a previous thread. I talked to my
wife (who is a geologist like me, but also has experience with waste water
treatement) about high pH levels some here have mentioned, and she pointed
out that high pH can also be an indication of high waste loads in the pond.
If the bottom of your pond (or rocks at the bottom of the pond) is covered
with black sludge and/or rotting detritus, you might want to try to clean
that up, and do a partial to full water change to see if that corrects the
problem. Just a suggestion.

George

George,

Does the sludge and rotting stuff push the pH down or up? I thought
it would move things in the acid direction.

Jim

in an aquarium it kills the biofilter and the nitrites which are acid
plus the organic debris which is acid drive the pH down. I would
imagine in a pond the same thing would happen, altho if there is just
high ammonia, that would drive the pH up.

I have never let my ponds get to sewage stage yet. Ingrid

On Tue, 3 Jul 2007 07:17:47 CST, Phyllis and Jim
wrote:
Does the sludge and rotting stuff push the pH down or up? I thought
it would move things in the acid direction.

wrote in message
. com...
in an aquarium it kills the biofilter and the nitrites which are acid
plus the organic debris which is acid drive the pH down. I would
imagine in a pond the same thing would happen, altho if there is just
high ammonia, that would drive the pH up.

I have never let my ponds get to sewage stage yet. Ingrid

On Tue, 3 Jul 2007 07:17:47 CST, Phyllis and Jim
wrote:
Does the sludge and rotting stuff push the pH down or up? I thought
it would move things in the acid direction.

That is true. However, few people build their ponds with an included
undergravel filter as is found in most aquariums. Most people who have a
biofilter (such as myself) build it as an enclosed structure or vessel.
Within that vessel, water is constantly being fed into it, bringing with it
oxygenated water. The sludge I was referring to occurs on the bottom of
the pond where detritus settles out and can become anoxic in areas with
little or no water flow, especially where there are rocks piled up. If
your biofilter is working properly, the nitrate and ammonia levels will
usually remain low, but the pH, over time will begin to rise because of the
build up of sludge on the bottom. That's my understanding of what happens.
It's a good argument for using sludge-loving bacteria in your pond to
prevent such build up from occurring, and also argues for increasing water
flow in areas where such build up can occur.

George.

that sludge is anaerobic, and anaerobic digestion releases hydrogen
sulfide H2S, which when combined with water is sulfuric acid H2SO4 ...
an acid. Nitrogen is released, bubbles rise to the surface and leave
the pond.

I would like somebody to do an experiment!!!! Ingrid

On Tue, 3 Jul 2007 14:57:25 CST, "George"
wrote:
The sludge I was referring to occurs on the bottom of
the pond where detritus settles out and can become anoxic in areas with
little or no water flow, especially where there are rocks piled up.
the pH, over time will begin to rise because of the
build up of sludge on the bottom. That's my understanding of what happens.

On Tue, 3 Jul 2007 14:57:25 CST, "George"
wrote:
The sludge I was referring to occurs on the bottom of
the pond where detritus settles out and can become anoxic in areas with
little or no water flow, especially where there are rocks piled up.
the pH, over time will begin to rise because of the
build up of sludge on the bottom. That's my understanding of what happens.
On Wed, 4 Jul 2007 11:33:21 CST, wrote:

that sludge is anaerobic, and anaerobic digestion releases hydrogen
sulfide H2S, which when combined with water is sulfuric acid H2SO4 ...
an acid. Nitrogen is released, bubbles rise to the surface and leave
the pond.

I would like somebody to do an experiment!!!! Ingrid

I was thinking similar. My understanding is when one has a build of sludge
one is heading for a pH crash, where it goes acidic. I suppose that could
be because the breaking down of sludge is also using up the buffering/KH.
~ jan
------------
Zone 7a, SE Washington State
Ponds: www.jjspond.us

"~ jan" wrote in message
...
On Tue, 3 Jul 2007 14:57:25 CST, "George"
wrote:
The sludge I was referring to occurs on the bottom of
the pond where detritus settles out and can become anoxic in areas with
little or no water flow, especially where there are rocks piled up.
the pH, over time will begin to rise because of the
build up of sludge on the bottom. That's my understanding of what
happens.
On Wed, 4 Jul 2007 11:33:21 CST, wrote:

that sludge is anaerobic, and anaerobic digestion releases hydrogen
sulfide H2S, which when combined with water is sulfuric acid H2SO4 ...
an acid. Nitrogen is released, bubbles rise to the surface and leave
the pond.

I would like somebody to do an experiment!!!! Ingrid

I was thinking similar. My understanding is when one has a build of
sludge
one is heading for a pH crash, where it goes acidic. I suppose that could
be because the breaking down of sludge is also using up the buffering/KH.
~ jan
------------
Zone 7a, SE Washington State
Ponds: www.jjspond.us

Sludge build up increases the total organic carbon and decreases the
dissolved oxygen in the water. Yes it does release H2S, but only when it
goes anoxic (otherwise, it can't support the anaerobic bacteria that
produces that gas). However, the acidifying effect of H2S production is
usually overcome by the changes in TOCs and DO, as well as gas exchange
into the atmosphere, which is where the H2S will end up if circulation and
pond surface area is adequate. Buffers can be depleted which can lower the
pH, but if you have a lot of carbonate rock in your pond (like I do) or
have a concrete pond, a significant reduction in buffering capacity is not
likely to occur. One thing is clear, and that is that a high pH is harmful
to both the fish and the plants in the long run, and should not be ignored.
So keeping sludge to a minimum and maintaining good water flow and
oxygenation is essential to a healthy pond.

George

wrote:
that sludge is anaerobic, and anaerobic digestion releases hydrogen
sulfide H2S, which when combined with water is sulfuric acid H2SO4 ...
an acid. Nitrogen is released, bubbles rise to the surface and leave
the pond.

H2S is an acid all by itself, without any need to react with water.
it's SO3 which reacts with water to produce H2SO4. The conversion of
H2S to SO3 is an oxidation reaction, which won't be happening in the
anaerobic areas of your pond. Also, where is the Nitrogen coming from?

George wrote:
That is true. However, few people build their ponds with an included
undergravel filter as is found in most aquariums. Most people who have a
biofilter (such as myself) build it as an enclosed structure or vessel.
Within that vessel, water is constantly being fed into it, bringing with it
oxygenated water. The sludge I was referring to occurs on the bottom of
the pond where detritus settles out and can become anoxic in areas with
little or no water flow, especially where there are rocks piled up. If
your biofilter is working properly, the nitrate and ammonia levels will
usually remain low, but the pH, over time will begin to rise because of the
build up of sludge on the bottom. That's my understanding of what happens.
It's a good argument for using sludge-loving bacteria in your pond to
prevent such build up from occurring, and also argues for increasing water
flow in areas where such build up can occur.

I can see how that works for small, decorative ponds. But what about
large ponds (say, one that is 100'x40' and 20' deep)?



--

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
Chris Barnes AOL IM: CNBarnes
Yahoo IM: chrisnbarnes
"Usenet really is all about standing around and hitting the ground
with clubs, on a spot where many years earlier a dead horse lay."

"Chris Barnes" wrote in message
...
George wrote:
That is true. However, few people build their ponds with an included
undergravel filter as is found in most aquariums. Most people who have
a biofilter (such as myself) build it as an enclosed structure or
vessel. Within that vessel, water is constantly being fed into it,
bringing with it oxygenated water. The sludge I was referring to occurs
on the bottom of the pond where detritus settles out and can become
anoxic in areas with little or no water flow, especially where there are
rocks piled up. If your biofilter is working properly, the nitrate and
ammonia levels will usually remain low, but the pH, over time will begin
to rise because of the build up of sludge on the bottom. That's my
understanding of what happens. It's a good argument for using
sludge-loving bacteria in your pond to prevent such build up from
occurring, and also argues for increasing water flow in areas where such
build up can occur.

I can see how that works for small, decorative ponds. But what about
large ponds (say, one that is 100'x40' and 20' deep)?


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.

George

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?


--

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
Chris Barnes AOL IM: CNBarnes
Yahoo IM: chrisnbarnes
"Usenet really is all about standing around and hitting the ground
with clubs, on a spot where many years earlier a dead horse lay."

Chris Barnes wrote:

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?

hurt. The water from the well is always going to be colder, so it will stay
at the bottom while the surface water cooks. Is that a problem? I'm not
sure. I think your fish will tend to seek, and prefer, the bottom water.
--
derek
- Unless otherwise noted, I speak for myself, not rec.ponds.moderated
moderators.

Derek Broughton wrote:
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?

hurt. The water from the well is always going to be colder, so it will stay
at the bottom while the surface water cooks. Is that a problem? I'm not
sure. I think your fish will tend to seek, and prefer, the bottom water.


Yeah, ok, I can see that.
So, assuming that it is better to put the cold well water on top, let me
ask a followup question.

The pond is not uniform in it's depth. One end is deep, the other is
shallower and has a small island (the depth from the bank to the island
is only 3.5' deep). I would assume that the best way to avoid the
stratification is to get the water to circulate, correct (or maybe not)?

So... would it be better to put the cold well water on the shallow end,
or the deep end? Or would it not really matter?

--

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
Chris Barnes AOL IM: CNBarnes
Yahoo IM: chrisnbarnes
"Usenet really is all about standing around and hitting the ground
with clubs, on a spot where many years earlier a dead horse lay."

Chris Barnes wrote:

The pond is not uniform in it's depth. One end is deep, the other is
shallower and has a small island (the depth from the bank to the island
is only 3.5' deep). I would assume that the best way to avoid the
stratification is to get the water to circulate, correct (or maybe not)?

So... would it be better to put the cold well water on the shallow end,
or the deep end? Or would it not really matter?

I think, technically, to put it in the shallow end, but I really have my
doubts that there's a point to it.

In the first place, I've seen arguments that you can't get any real
stratification in a small pond - I can't say, as I've never tried measuring
the temperature at different depths. Beyond that, I don't see
stratification as any kind of risk. When it's 95F outside, and you've got
60F well water coming into the pond, I bet you see your koi congregating
whereever the cold water comes in - whether that's at the surface or at the
lowest point.
--
derek
- Unless otherwise noted, I speak for myself, not rec.ponds.moderated
moderators.

"Chris Barnes" wrote in message
...
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?

The main issues, as I see it, are what is the salinity (i.e., total
dissolved solids - TDS) of the well water you intend to use as well as the
pH, and how well oxygenated it is. Well water generally is not well
oxygenated since it is sequestured below ground and so doesn't get good gas
exchange, and is often quite saline, so if it were me, I'd run the water
over a waterfall or create a fountain that would agitate and add oxygen to
the water. Alternatively, you good build a 30 gallon oxygenator using a
plastic chemical drum, and pump air through the water before it is pumped
to the bottom of the pond. That remedy, however, might be more expensive
than to simply create a cascade of water into the pond. That would solve
the oxygen problem (if one exists).

As for TDS, your water well driller usually will attempt to tap an aquifer
that is low in TDS but that is not always possible. For drinking water
purposes, drillers have often had to rely on installing whole house reverse
osmosis units to get rid of the high TDS if there is not other alternative.
Just remember this; the EPA allowable levels of TDS in well water for
drinking water purposes cannot exceed 500 parts per million. If your water
is below that limit, you should be ok. When you have your well drilled,
ask the driller to test for TDS (in most states that is a requirement),
fecal coliform, and dissolved oxygen (DO) at a minimum. You may want to
ask your state department for natural resources what the testing
requirements are for new water wells in your state, and make sure your
driller follows their guidelines (drillers are notorious for cutting
corners, so arm yourself with the right information and watch him like a
hawk).

As for stratification, all you need to do to prevent that from occurring to
to make sure there is a constant flow of water that turns the water over.
Pumping the water into the bottom is one method. You could also install an
aerator that will pump a curtain of air (at least half way down) and let
the bubbles create an upflow of water, allowing the water to be constantly
over turned. Don't install either straight on the bottom, since that could
stir up bottom sediments and cause your pond water to become turgid
(cloudy). Another method I've seen that is related to the aerator method
is to create a sort of water feature out of it. You pump air into a pipe
(from the bottom) that is suspended in the water column. The pipe only
need go halfway down in the water. At the top, you create some kind of
scupture like a spitting fountain (works best if it is not too far above
the top of the water). I've seen people make a feaure that floats on the
surface but remembles a grist mill stone with a hole in the middle. The
aerated water then flows over the surface of ther "grist mill stone" and
flows back into the pond. The air will pull the water from the bottom to
the top and "spit it out" just like a riser pipe on an undergravel filter
in an aquarium, adding oxygen to the water and creating a vertical
cirulation of the water column. Just remember that pumping air ten feet
down is going to require a substantial air pump. A simply aquarium air
pump will not do. Here is a self-contained aerator that is said to work
well.

http://www.livingwateraeration.com/pa33.html

If you decide to install a water pipe from your water well near the bottom
of your pond, you could combine an aerator with it and kill two birds with
one stone. That would also prevent evaporation loss because you are adding
water to the pond as you are aerating it.

Good luck.

George