I can't tell you what will work but my experience might help you. I
started with green water and ended with clear. I have a 1300 gallon
pond, 2 koi, 2 dozen shibunken, half dozen lillies and iris. Before
last year it was all green soup below 4 inches. I tried adding plants
(they looked anemic) and adding potash and potasium and iron (no change)
and growing more lillies for shade (no change). My filter, at first, was
lava rock (it plugged quickly with green muck) and then I tried an in
pond filter (it just failed to do much). I've never had a problem with
ammonia, nitrates, etc. Last year I added one of those big feed tanks
and added 25,000 drinking straws. Not quite a month later my pond turned
clear. I can see shadows on the bottom (3 feet). At the end of last
year I looked and many of the straws were plugged and possibly the water
was just going around the others. Also there was a thick layer of muck
on the bottom of the filter (but not on the pond). I've read that
rotting algae creates an algicide and I assume that my filter formed a
place to catch algae, let it rot, and run the water past it. Before this
season I cut up the straws into little pieces so they were easy to work
with in the filter. I noticed a week or so ago that there was a big
hole in my pile of straw bits so it might be that the water is still
going around the bulk of my filter. I still have clear water. I also
fertilized the iris (I've always fertilized the lillies). Since the
iris are in pea gravel I assume fertilizer got into the water. So, the
iris are going crazy and the hyacinth are going crazy and the lillies
are even doing better. Now my only problem is that all of the roots from
the plants are making a nice place for string algae to collect. I got
some bottled bacteria and increased the water circulation and now I'm
waiting to see what happens. So far it seems better than before but it
could be that the fertilizer level is dropping. I'll try fertilizing
the iris again as a test.

So, I'm not sure I need anything more than a big settling tank and
filter media that has lots of large gaps. Big enough not to plug but
small enough to catch algae that can rot. The type of filter media with
the tiny holes would never work in my pond.

Matt


John wrote:
hey everyone. ive been working on my pumps and filtration methods. i used
to pump about 8 gallons a minute through a somewhat thick filter material
and within a week my pond was pretty clear. at the time the filtered water
went directly into the pond from the filter material. now, i have about
10-15 gallons per minute cascading down a waterfall and the top is filled
with hyacinth. there is no filter material now... when i use filter
material (even with the old set up) i was cleaning the material almost
everyday. i havnt had to change it all now with the hyacinth as my filters,
but the pond is completely green now. what should i be doing in order to not
be cleaning my filters everyday and get my pond back to being clean. The
filer is about 1 foot off the bottom of the pond so it doesnt pick up any
muck.. is this correct? any help is appreciated
thanx!
John