I recently picked up my dogs from Karen, the dog groomer, and we started talking about gardening. Karen has been steadily adding shrubs and trees to her property for several years now. She has a small pond, and two years ago, had it repaired because of a leak, but the pond still has cloudy water.
First of all, I am not a pond expert, but I have been closely observing my pond for the past seven years. In 2008, I wrote a piece for Kaatskill Life about the problem of pond algae. See Kaatskill article:
A Blooming Pond, for a more in depth discussion.
Karen also mentioned she had tried numerous brands of natural pond bacteria, but none of those products helped with the cloudy water. Her pond is stocked with koi fish, and after a quick search on the internet, I discovered that sometimes the cloudiness may be a result of over feeding the fish. The unconsumed food breaks down and clouds the water. I also suggested to Karen that she create a buffer zone between her lawn & the pond edge. By planting plants, or as I did by just letting the wild flowers arrive- the plants will act as a filter system to the grass clipping that break down into acidic runoff. I think most healthy ponds have plenty of vegetation both in the water and around the pond.
Please see below the series of photographs showing the development of my pond over the years and how the “Buffer area” which is so practical, has become a beautiful part of the garden.
Client’s pond recently dug and seeded.
My pond, first year- grass has filled in.
2nd year, bishop weed, daisy and clover show up in buffer area around pond.
Year 7: Arctic willow , flag iris and many more meadow plants are established.
Rooting for Ideas 
Thanks, Don. It really does not seem like we are feeding them a lot; but we will try giving them a little less. Eric is going to pick up barley straw today so we’ll see how that goes and keep you posted. Thanks for the suggestions!
Hi Karen,
The water in our ponds here in the western Catskills does appear brown because of the heavy clay soil, but what I saw in your pond was a cloudy film instead of clear water. You mentioned a couple of times the “brown color” – so I wanted to say that that is normal. Hope the problem clears up!
Yes, I agree- it’s really more the cloudiness than the color that’s at issue.
What a beautiful property you have Don.
I am not an expert on ponds, but one of my friends in Denmark who also have lots of koi fish made a filter for the pond using lots of willow cuttings. Here is link to a post about it on her blog, if you are interested: http://willowdane.blogspot.com/2011/03/det-er-forar-og-jeg-er-nsten-frdig-med.html
Hi Lene, Thanks for posting that interesting Danish site. I just clicked a button and the Danish changed to English- so cool.
Koi would not work here in the wilds of the western Catskills. We have a lot of blue heron and they would empty the pond in no time.
I have actually scared a blue heron and he dropped a brown trout from my pond. It’s hard enough keeping brown trout in the pond even though it’s 16′ feet deep.
I have several willows growing around my pond: Arctic willow, Rosemary willow and Britzensis. But I have the bug and want more.