"Mark Kelly" wrote in message
...

I know this will have been covered before but...

My 3 foot deep, 6000 litre pond is about to start it's first winter.

My water temperature is 5 Celsius and the fish have started to slow
down.

When should I turn off my pump/UV and what else should I be thinking
about.


Slippers.

My pump runs 24/365 providing oxygenation year round. Although I do not use
a UV filter, I guess that could be switched off as algae growth will be at a
minimum. As plant surface cover will be dying back you could consider
providing floating mats or submerged 6" drainage pipes to provide 'natural'
hiding place cover for the fish. Reduce feeding from daily to weekly to nowt
when frost and ice is on the pond.

................. And enjoy your central heating. :-)

--
ned

Mark Kelly writes

I know this will have been covered before but...

My 3 foot deep, 6000 litre pond is about to start it's first winter.

My water temperature is 5 Celsius and the fish have started to slow
down.

When should I turn off my pump/UV and what else should I be thinking
about.

I use 10°C as my guide. Once the air temperature reaches that I stop the
pump and the waterfall for the winter. The water then cools and settles
into stable thermal layers, the bottom (densest) never going below 4°C.
The oxygenating plants in the water do the rest, and the many fish have
lived and bred happily for a number of years.

If you leave the pump on when it gets cold, then you will ensure that
all levels in the pond are reduced to the same outside ground
temperature.

I removed unwanted plants and dead matter earlier on when it was a bit
warmer (for me), but I'd leave them be now and do it in the spring.

I don't feed the fish much anyway, but even less now, and not at all if
I can't see them moving actively. I also don't break the ice or fuss
about keeping it clear. To be honest, it rarely lasts more than a few
days at a time, even if thick enough to walk over. No-one clears it on
natural ponds.
--
David

in article , Dave at
wrote on 21/10/02 12:56 PM:

Mark Kelly writes

I know this will have been covered before but...

My 3 foot deep, 6000 litre pond is about to start it's first winter.

My water temperature is 5 Celsius and the fish have started to slow
down.

When should I turn off my pump/UV and what else should I be thinking
about.

I use 10°C as my guide. Once the air temperature reaches that I stop the
pump and the waterfall for the winter. The water then cools and settles
into stable thermal layers, the bottom (densest) never going below 4°C.
The oxygenating plants in the water do the rest, and the many fish have
lived and bred happily for a number of years.

If you leave the pump on when it gets cold, then you will ensure that
all levels in the pond are reduced to the same outside ground
temperature.

I removed unwanted plants and dead matter earlier on when it was a bit
warmer (for me), but I'd leave them be now and do it in the spring.

I don't feed the fish much anyway, but even less now, and not at all if
I can't see them moving actively. I also don't break the ice or fuss
about keeping it clear. To be honest, it rarely lasts more than a few
days at a time, even if thick enough to walk over. No-one clears it on
natural ponds.

I don't think that having a pump running in a pond is going to make any
difference to what the water temperature is. For a pond to be effected by
'layers' in the winter it's probably going to need to be in the in the
region of about 100ft + deep. For a 3ft deep pond the water surface temp
will be the same as the bottom temp whether the pump is running or not. If
anything having the pump running will prevent the ice forming where the
water runs back into the pond.

For a pond to be effected by
'layers' in the winter it's probably going to need to be in the in the
region of about 100ft + deep. For a 3ft deep pond the water surface temp
will be the same as the bottom temp whether the pump is running or not.


No it won't. If it was, ice would form at the bottom of 3' deep ponds. As it
is ice is less dense than the water at the bottom of the pond (which is densest
at 4 degrees centigrade) and so forms on the surface of the water/pond.

Pumps should be turned off over winter, and ice which forms on the surface of a
pond should be melted to allow the escape of toxic gasses that can build up
over time. Breaking the ice using physical force can injure the fish in the
pond.

I hope that this clears a couple of points up.

Dave.

DaveDay34 wrote:
For a pond to be effected by
'layers' in the winter it's probably going to need to be in the in
the region of about 100ft + deep. For a 3ft deep pond the water
surface temp will be the same as the bottom temp whether the pump
is
running or not.


No it won't. If it was, ice would form at the bottom of 3' deep
ponds. As it is ice is less dense than the water at the bottom of
the pond (which is densest at 4 degrees centigrade) and so forms on
the surface of the water/pond.

Pumps should be turned off over winter, and ice which forms on the
surface of a pond should be melted to allow the escape of toxic
gasses that can build up over time. Breaking the ice using physical
force can injure the fish in the pond.


My pump runs 24/365. The running water ensures open water at the
inflow during freeze conditions. And my fish survive - to my
knowledge, for twelve years they have survived.
Oh, I *will* endorse the warning about not physically breaking surface
ice. Quite right, sir ...... although I've never faced the need.

--
ned

In message , ned
writes
DaveDay34 wrote:
For a pond to be effected by
'layers' in the winter it's probably going to need to be in the in
the region of about 100ft + deep. For a 3ft deep pond the water
surface temp will be the same as the bottom temp whether the pump
is
running or not.


No it won't. If it was, ice would form at the bottom of 3' deep
ponds. As it is ice is less dense than the water at the bottom of
the pond (which is densest at 4 degrees centigrade) and so forms on
the surface of the water/pond.

Pumps should be turned off over winter, and ice which forms on the
surface of a pond should be melted to allow the escape of toxic
gasses that can build up over time. Breaking the ice using physical
force can injure the fish in the pond.


My pump runs 24/365. The running water ensures open water at the
inflow during freeze conditions. And my fish survive - to my
knowledge, for twelve years they have survived.
Oh, I *will* endorse the warning about not physically breaking surface
ice. Quite right, sir ...... although I've never faced the need.

where in the UK are you Ned / DaveDay ?
--
dave @ stejonda

calculate your ecological footprint http://www.lead.org/leadnet/footprint/

in article , DaveDay34 at
wrote on 28/10/02 4:32 PM:

For a pond to be effected by
'layers' in the winter it's probably going to need to be in the in the
region of about 100ft + deep. For a 3ft deep pond the water surface temp
will be the same as the bottom temp whether the pump is running or not.


No it won't. If it was, ice would form at the bottom of 3' deep ponds. As it
is ice is less dense than the water at the bottom of the pond (which is
densest
at 4 degrees centigrade) and so forms on the surface of the water/pond.

Pumps should be turned off over winter, and ice which forms on the surface of
a
pond should be melted to allow the escape of toxic gasses that can build up
over time. Breaking the ice using physical force can injure the fish in the
pond.

I hope that this clears a couple of points up.

Dave.

Dave,

If it's say January / February. The pond is 3ft deep and is unfrozen at the
surface. Do you expect there to be a difference in the temp from the top 6
or 12 inches to the bottom at 3ft.

From past experiences I'd be very surprised if there were. The reason being
that as well as being interested in gardening & ponds etc.. I'm also a diver
and continue diving throughout the winter (in inland lakes). During the
winter months (Dec, Jan, Feb, March). During this time the surface water
temp remains the same as what it is at 22mtrs (usually around 3 or 4 deg c)
It's not until you drop down to about 30 - 36 mtrs that it 'warms up' to
about 9 deg which from my records seems to be the constant year round temp
for this depth.

Hence my reasoning that 3ft just isn't enough depth for a difference to be
noticed from the surface.

I do agree about breaking the ice though. Although as someone else has
mentioned, you don't have to break it if the pump is still running as the
movement of water keeps it from freezing.

Regards, Ian.

dave @ stejonda wrote:
In message , ned
writes

snip
My pump runs 24/365. The running water ensures open water at the
inflow during freeze conditions. And my fish survive - to my
knowledge, for twelve years they have survived.
Oh, I *will* endorse the warning about not physically breaking
surface ice. Quite right, sir ...... although I've never faced the
need.

where in the UK are you Ned / DaveDay ?

East Midlands - which isn't renowned as the English Riviera and
certainly won't sustain outdoor grapes. :-)

--
ned

In message , ned
writes
where in the UK are you Ned / DaveDay ?

East Midlands - which isn't renowned as the English Riviera and
certainly won't sustain outdoor grapes. :-)

thanks - so my 3ft pond with pump left running should be fine except in
extremis

--
dave @ stejonda

calculate your ecological footprint http://www.lead.org/leadnet/footprint/

I live in N. London and the advice I gave about pumps and breaking ice, etc. is
what is generally accepted as being what you should do. I almost put in a
caveat that there may be regional differences, but thought that most people
would allow for this anyway.

With regard to diving, I think that divers are unlikely to be interested in the
microscopic variations in water temperature, where as keepers of fish in ponds
will be. Divers are more macroscopic about there water temperatures, so to
speak. The other issue is water depth. Without wanting to get all technical,
water in a shallow pond (relatively speaking) will behave differently to water
in the sea, an estuary/river, or a gravel pit that's been flooded. I really
don't want to get into a discussion about water temperature profiling of
lakes/ponds etc. Apart from anything else it' just take too long, and there'd
be little point to it all.

Happy diving/fish keeping.

Dave.