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Derek Broughton · 05-05-2008, 06:59 PM posted to rec.ponds.moderated

wrote:

I'm interested in keeping Koi, but even a cursory glance over the
literature is giving me second thoughts about a few issues. Here's a
description of the pond:

Size: about 8 x 8m (24x24 feet)

Depth: around 50 cm ( 2 feet)

It's a bit shallow for koi, but people have kept them in worse...

The gardner has already installed a fairly hefty multi-chamber filter
of (very) approximately 300L (60 gallon?) and an ultra-violet unit.

If you _don't_ have koi, the UV (and filter) is pretty pointless - a water
garden with only plants will stay clear on its own without

They've also currently planned a series of fairly powerful underwater
green lights.

A lot of things give me concerns there and this was clearly never
planned as a Koi pond..

1) depth: is it at all deep enough to keep koi or any other fish?

It's deep enough in most places to keep goldfish.

The filter will obviously be kept running during the winter months and
I imagine that this will help with the freezing.

That's not really "obvious". One big problem with running a waterfall in
winter is ice damming. It's possible for ice to build up in such a way as
to redirect water flow out of the pond. If that can happen, you're much
better off to turn off the waterfall.

I also wouldn't mind
heating part of the pond with an immersion heater,

That will cost you a fortune.

but it might yet be too shallow for a Koi and/or winter.
I live in Luxembourg between
Germany and France, so we don't have Scandinavian winters but
temperature do occasionally drop under -10C.

Not really. It would be a good idea to insulate those concrete walls,
between the concrete and the liner, with at least 3" of foam insulation,
but then conductance from the soil beneath the pond should keep it from
freezing solid.

2) metal grid/ child safety

Are Koi surface feeders? would I be able to feed them properly? will
it stress the fish?

Many people have done this, it shouldn't be a problem. They're not strictly
surface feeders, but they will come to the surface if food's there. They
can suck pretty well :-) If the grid is only an inch below water surface
they won't have trouble. What size is the grid? If the spacing is more
than 3", they probably won't even notice it.

3) lighting during the night?

I'm not sure yet how strong this lighting will really turn out to be,
but is this a problem for Koi?

No idea, but you'd want a switch anyway, wouldn't you? There's no point
leaving the lights on if nobody is there to see, unless you're thinking of
it as a safety feature (being able to _see_ if your child's in the pond -
in which case motion detector external lights are probably more use).
--
derek