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

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)?



--

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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