As Sean has said your idea for a pond is way too small. The larger the pond
the easier it is to take care of. As for filters, look at some of the
references on rec.ponds to the veggie filters, which are basically a
separate shallow pond filled with plants and a slow flow rate. These are
probably the best filters for the money, at least for ponds that aren't
extremely overcrowded with large fish. The koi will grow, and grow large.
Many of mine are in the size of approximately 24 inches, and would not be
able to turn around in the preform ponds, and with so little water, it would
require some real powerful filtration to maintain the water.
--
RichToyBox
http://www.geocities.com/richtoybox/pondintro.html

"Sean Dinh" wrote in message
...
Raising that much fish in a small pond requires a great
filter. In intensive aqua culture, catfish are raises at 9
lb per cubic feet. That is equivalent to 7.5 gallons for 9
lb. Koi are raised for their color and swimming posture.
That's why Koi aficionados recommend significant amount of
water.

For only 4 koi, I would make a nice formal pond with size
6'x10'x1.5'. That's 675 gallons. You could have 150 gallons
pond, but you lose the other aspect of Koi, as in viewing
them swimming. If the pond is only 1.5 feet deep, like most
preforms, you don't need to get a permit for it. People here
in SoCal have to have a fence around their deeper ponds.

Some people like plants in their ponds, some don't. Plants
in a pond have a few useful purposes. They remove nitrate
from the water. They don't require power, so they help the
pond when the pump dies. They are toys for the fish to play
with. It's up to you. If you want plants, you need to make
the pond bigger.

There are many filters, as in mechanical and biological.
Sand and Bead filters are expensive, and need a lot of power
to run. They are near the top of biological filters.
Fluidized bed filters are the top, as far as ammonia removal
is concerned. The don't require much power. Submerged
filters are ok. They don't require much power, nor cost much
to make them your self. The other filters are Trickle Tower.
They don't require much power, and are simple to make.
Beside basic filter function like the others in removing
ammonia, they aerate, remove nitrate, and degas the water.
However, like submerged filters, they are not as efficient
as Bead nor Fluidized. These latter filters are 4-10 as
efficient.

For the best water, in look and suitability, you need 2
filters. The Bead filter to remove ammonia and polish the
water. The TT to fill in the rest of the deficiencies. In
your case, the options are submerged and TT. I prefer TT.
Most others prefer submerged.

Pumps are required to circulate water through the filter.
Size requirement is due to 2 factors. One factor is how much
mechanical filtration you need. Clean pond requires a lot of
water circulation to filter the debris. The other factor is
feed. If you feed the Koi a lot, you need to push a lot of
water through the biological filter. For the recommended
pond, my guess is 1000 gal/hour pump is good. For this size
pump, I would use Laguna pump in the price range of $100.
For this 70 watts pump, you would be looking at $7 per month
on electricity.

Algae are everywhere. Whether you need a UV light to kill
them depend on your pond and biological filter. You could
build your pond, and find some remedies on this group to
cope with green water. The easy route is to install one.
Some people run their UV lights year round. Others shut them
off when the green water cleared.


charlie thompson wrote:

Am Involved with real estate, and a seller had a small koi pond about 5
X 7 ft. and about 30 inches deep. This seller left for new home, and
new owners did not take possession until 3 months later. I took it upon
myself to feed fish every other day as i live a distance from other
house.

The pumps were turned off for about a month, and the water was murky,
dark brown, and one could not see beyond the surface. When I fed fish
few would venture to the top, and so I remained about 10 minutes and
left.

I thereafter determined to get the pump running, and after reading koi
articles determined that I might be able to do water changes to get the
water cleaner.

After changing water about 10% every other day, I determined there were
55 yes 55 koi living in this small pond. They were about 5 that were 10
to 20 inches, and the remaining were 5 to 8 inches.

A storm occurred here and trigs were in the pond, and a puncture in
the liner occured and there was only about a foot of water remaining. I
did not know if the bottom of the liner was where the tear happened, so
I just kept adding water each day to keep the level up. I thought
better to have some water then none at all.

Half the fish died, most the larger. The remaining fish were taken
away, as I found a supplier who wanted about 25 or so of them. I took 4
small ones [about 4 to 5 inches] and they have been living in my garage
for 3 months, in a 20 gallon tank.

Hearing all about space needed, and the special care required, and then
seeing 55 koi live in such a small place, I'm perplexed. I'd like to
have a small pond of about 180 gallons. How to keep these 4 alive on
outside ? Do I need special filters, pumps, those lights that kill
algae? Being on fixed income can
I find more econonically, less costly pumps, lights, etc so my electric
bill is not sky high.? Any recommendations? Suggestions? name brand
recommendations? Thank you. I really like to keep these guys alive.

--
charlie thompson

You might want to start small and work your
way up. See if you get bit by the pond bug and
then go for koi and really give them all that they
need.

You can start with 180 gallons but put in three or
four goldfish. You can filter the pond with plants
(this only works with few fish to much water
and many plants)
in the pond and run a pump set up with a fountain.
That's the simplest and cheapest way to start a pond.
Then you can get a feel for it, save money, read a lot
and build something bigger for koi. As you saw they can
get really big!

I have goldfish and a couple of koi in 3,000 gallons. I filter
the pond thru watercress in the waterfall and water hyacinth
in the waterfall pond once May comes (when it becomes warm
enough for this tropical plant).

If you are handy there are many do it yourself filter plans out
there (many rec.ponders have them) and build a filter to handle
a larger pond and bigger fish load.

You will get lots of good information here. You can pick and
choose whatever feels right for your situation.

kathy :-)