You can get these in Bunnings, I have one working on my pond. It is a black
plastic box about 450mm X 300mm X 300?mm deep and inside it at the bottom
(side) is an outlet pipe with clear plastic tubing that hangs into the water
and packed inside it are convoluted small pieces of pipe (like agg. pipe and
on the top of them are two pieces of (fine) foam about 50mm thick and at the
top of these is a piece of rougher foam that on the top is shaped like egg
carton ridges.The water is brought into the box at the top side and it is
connected to a pvc pipe with holes underneath that the water flows through,
the end of the pipe is blocked off. This filter is called a biological
filter, the first time you use it you go to an aquarium shop and get a
little bottle of ( i forgot what it's called) but you empty the bottle into
the pond water and the organism work their way into the filter and live in
the convoluted piping and they eat the matter that the water brings down to
them and they help to keep the water clean and healthy. You have to make
sure when you clean the foam pieces out that you don't let the box dry out
as this kills the organisms, might pay to buy some spare pieces of foam just
to cahnge straight over when cleaning the filter as these are pretty
inexpensive. Hope this helps you.
"David Thomson" wrote in message
...
I'd like to make one to keep my fish pond (which gets a lot of sun in the
summer) clear of gunk and algae and would be most grateful if someone
could
steer me in the right direction.
Cheers
David