to build a koi pond filter!
a pond filter is a relatively easy task. The goal is to
change the water 10-20 times an hour while keeping most of the big
stuff trapped in the filter. The filter is a biological
master piece. It is a good thing we do not need to know the
details. We just need to have plenty of room for the good
bacteria to hang out and do their thing. Look at the pictures
below. The first 6 pictures are pond and fish pictures.
The plant shelf behind the fish is 24 inches long.
Notice the cup with soaking fish food in the sixth picture.
If you soak your fish food for 20-30 minutes before feeding
the fish, they digest the food better resulting in less waste being
generated. Less waste, means less pond cleaning.
Pictures 7 & 8 show the difference between tap water
and pond water. The pond water on the right is supposed to be
The second row of pictures is the materials used to build the filter.
The materials are the type of stuff that most pond owners
collect becuase there may be a need for it some day. The 50
pound bag of carbon can be found at a local GE/Ionics water supply
store for about $30. If you don't feel like tracking the
local water supply store down, you can buy a 5 gallon bucked off ebay
for around $30. I got most of my stuff from a local drug
manufacturer. They generate a lot of waste because of their
standards. The 4th and 5th pictures show the roof gutter that
I used for water return. The 8th picture shows a piece of
downspout with a whole bunch of holes drilled in it. The
holes are to keep the fish from getting sucked into the pump intake.
The first picture on the third row shows a 5 gallon bucket, half full
of small stones, sitting in the middle of a 50 lb bag of carbon at the
bottom of the barrel. The stones are to break up the water
current from the pump. I don't really want to disturb the
carbon at the bottom. I want it there to hold bacteria and
remove the chlorine. The next picture shows how I inserted
the intake pipe into the home made intake guard. The third
picture shows how I use two pipes into the stones to spread distribute
the water across the stones. The valve in pictures 3 and 4 is
to control the water flow into the filter. Too much water
into the filter can result in a spill over the sides of the filter.
Picture 6 dipicts the good old fashioned hot glue gun to glue
the gutter to the drum. I was told to buy all of this
expensive fish friendly glue but the hot glue does not seem to have any
adverse affects on the fish. The 7th picture is a feeding
frenzy. The eight picture shows the filter media raising up
much higher than I anticipated. This had to be corrected by
removing some of the floating media and intalling a tie bar to prevent
the media from covering the overflow pipe.
Make sure to remember that ponds are living things and require time to
adapt. The water should always be to dirty to drink.
Koi fish like to swim in currents. I change the
currents regularly. Do not clean the filter often.
The filter can smell bad. The water should not
smell bad. Never change more than 20% of the water per week.
I do about 10 water changes per year of about 20%.
UV lights are very helpful in keeping the water clear.
There is no getting around the $100 for the UV light.
This type of filter is an up flow style where the debris stays below
the filter media. AFter the filter is built and running, you
can surround it with T-11 siding or painted wood for aesthetics.