Pond Construction - Thermal Insulation

Hi All, I've been lurking on the ng for a while now... I'd like to ask a
question.

My wife and I have kept Koi for a few years now - originally they were hers
(married a year ago and she had them before we met) and she used to have a
number in a very small back yard pond (they were very small back then),
which was however fully filtered etc.

We have since moved, and moved them by using a Vat - 1000 gallon, which they
have been ok in, fully filtered of course. In fact more than fine, water
quality great, and fish have grown - a lot!

We are now in a position to build a proper pond, 3000 gallonish. (so 2*5*1.5
meters ish), so we will be getting a new filter system and heaters. All they
previous ponds have been heated - including the vat - which had bubble wrap
around it to prevent excessive heat loss during winter (and thus excessive
electric bills).

She still wants to heat the new pond to some degree. question, on a sunken
pond is there any standard way of trying to minimise heat loss through
design / construction of the pond?

Your views appreciated.

Kev (and Julia)

"Kev" <> wrote in message
news:_LOdnSBe7a1Ti-...

> She still wants to heat the new pond to some degree. question, on a sunken
> pond is there any standard way of trying to minimise heat loss through
> design / construction of the pond?
>
> Your views appreciated.
>
> Kev (and Julia)
>
You don't say where you are located or what depth the ground will freeze in
your area, so I will give my general feelings. I have two ponds, one 4000
gallons and one 3500 gallons that are both heated to around 70F (20C). The
most important thing that you can do to heat a pond is to put some type of a
cover on it to minimize evaporation. Evaporation really cools the pond. I
cover mine with a lean-to structure that can be seen at
http://www.geocities.com/richtoybox/pondpage3.html. This structure gets
covered with a solar swimming pool blanket that looks like bubblewrap and
two layers of polyethylene sheeting. It accumulates some solar heating and
helps retain the heat in the pond. The earth at a couple feet below the
frost line is pretty constant temperature around 50 degrees F (10C). This
relatively warm earth will act as a heat source if the pond temperature
falls to below this temperature, so I don't like to see it insulated. The
walls of the pond, near the surface might benefit from some insulation,
since the frozen soil would rob more heat from the pond.

Rich.. "This increased the size to about 220 gallons."?????? you mean
increased to 2200 gallons?

I am in zone 5-6, 10 below in winter, sometimes -20. I too cover the
pond with plastic to minimize evaporation which carries the heat away.
In addition, I constructed my pond with a stud wall that is insulated,
altho if I do it again I will use blow in expanding foam which is
water proof and seals really well.. wood is a very good insulator,
BTW. the bottom of the pond is only insulated with the carpet foam
stuff. actually it is pretty good insulation. My pond stays 50-55 for
all but 1 coldest month with a single 500 watt heater. And my pond is
1.5 feet above ground.
This year the pond is going to have double plastic since I am
enclosing the area around the pond (for sitting) and enclosing the
pond itself with a little lean to.
http://weloveteaching.com/mypond/winters/winter.htm
Ingrid

On Mon, 18 Jun 2007 06:43:06 CST, "RichToyBox"
<> wrote:
>You don't say where you are located or what depth the ground will freeze in
>your area, so I will give my general feelings. I have two ponds, one 4000
>gallons and one 3500 gallons that are both heated to around 70F (20C). The
>most important thing that you can do to heat a pond is to put some type of a
>cover on it to minimize evaporation. Evaporation really cools the pond. I
>cover mine with a lean-to structure that can be seen at
>http://www.geocities.com/richtoybox/pondpage3.html. This structure gets
>covered with a solar swimming pool blanket that looks like bubblewrap and
>two layers of polyethylene sheeting. It accumulates some solar heating and
>helps retain the heat in the pond. The earth at a couple feet below the
>frost line is pretty constant temperature around 50 degrees F (10C). This
>relatively warm earth will act as a heat source if the pond temperature
>falls to below this temperature, so I don't like to see it insulated. The
>walls of the pond, near the surface might benefit from some insulation,
>since the frozen soil would rob more heat from the pond.

Thanks both!

We live in Scarborough UK, so ground rarely freezes, although a Easterley
wind can be really bitter

Kev

We live in Jackson, MS, but used to live in Cambridge, UK. I am
wondering how much insulating would actually help your ponding
experience.

Our pond here seldom has more than a few days with ice on the top.
Our external temp is generally in the upper-30's to upper 40's in the
winter. We have not insulated or covered our cement pond at all.
That means the temp does go down to air temp quite fast. The koi do
fine, but are pretty inactive when the temp gets really down. We
don't feed them once the water reaches 50 degrees.

I am not sure how insulation would benefit them or us if it did not
keep the water high enough to feed them. Even then, I suspect it
would reduce the amount of time under 50 rather than eliminate it.
Jan may have some wisdom about how we would benefit if we insulated.

I think you will love your larger pond. People here might have a lot
of suggestions about how to reduce the amount of maintaining work to
be done.

By all means post some pics as your work moves ahead.

Jim

there are two problems with "under 50" temps, one is their immune
system shuts down, the other is up here in the frozen tundra without
covering and heating the fish must go for 6 months without food and go
thru a long transition to upregulate their immune system. I think it
is hard on koi. My koi are much healthier since I started heating the
water and feeding them most of the winter. Ingrid

Kev wrote:
> Thanks both!
>
> We live in Scarborough UK, so ground rarely freezes, although a Easterley
> wind can be really bitter
>
> Kev
>

I'm further South than you being in Berkshire......the ground certainly
does freeze here but we are not by the coast.....having been in the
planning stages for quite a few years I've worked out the frost
line.....from my understanding you need to be quite a few inches under
this - mine is about 6" of frozen ice in a bad winter.......Of course
being by the coast your less likely to suffer the severe frosts that we
do.....but I've also seen pics of Yorkshire in winter......dig deep
would be my advice and afterall if you are housing Koi then you need to
do this anyway......IIRC Jan put first suggested the concept of heaters
to me.....take a look at these:-

http://www.aquatics-online.co.uk/cat...r-nets-etc.asp

Gill

Thanks for the replies

Last winter we had them in the Vat, with 3 layers of carpet under them, and
treble layers of bubble wrap around them. The result was they they were nice
and cosy at 17C. However I should have had shares in Npower... !

Kev