Topic: green water

[tomatoada]

My small garden pool which I put in last year in early Spring, was quite a success. The water  cleared. The plants grew ,so did the fish and we had some babies.  We had some blanket weed which I took out with a stick. No problems
 This year the water has turned a murky green and stayed that colour since April/May.  The fish only come to 3 or 4 inches below the surface.  Just a slight movment of orange is all I see.   Any advice please.

[Margaret]

We have had so much sun it has caused this algae bloom that the plants have not been able to compete with.The fish are also adding to the rich nutrients that feed algae,especially if they have young ones.The pond would greatly benefit from a pump,a filter and some more shade giving plants such as water lilies.The smaller the pond the harder it is to get a good balance.

However the good news is that while you have this pea green effect you will not encounter any blanketweed and in fact,green water is a sign of a reasonably healthy pond.Be sure not to keep too many fish though or you may  find you will begin to have a lot of problems with their health through water quality.

[tomatoada]

Many thanks for your reply.  I have only 3 big fish about 3 inches long and 2 or 3 baby fish about 1 inch.  The pool is 36 inches round and 18 inches deep. My garden is so small a bigger pool would look out of place. There is no shade which I would like to change.  There is no electricity to the pool so I can't put in a pump. 
The pool  looks so awful I might remove it.  It was such a pleasure to sit by last year and watch the fish in clear water.
If I half cover it with a piece of wood would it help?  Again thanks.

[WASSISNAME]

Maggie, don't give up on your pond, we had the same problem this year with the green water, but having been given a lot of parrotts feather oxy weed 2 weeks ago the pond is now beginning to clear and we can see the fish again

[tomatoada]

Sounds good this parrotts feather oxy weed but where can I get some please?  Tried the R H S site and aquatic plants.  No luck.  Got some weird  sites about welding ect..  Has it got another name?

[gardenqueen]

Parrots Feather is effective but is very invasive. It has been known to get into our rivers and streams and has caused untold damage. I am pretty sure that garden centres no-longer sell this plant, or, if they are, they shouldn't be!

[tomatoada]

Oh dear!!!

[WASSISNAME]

I got mine from a friend who has a pond, but I have seen it in water garden centres. I know that Mares tail is invasive and can get into the soil around the pond, that looks like small christmas trees, but I think that Parrots feather is o.k. I don't know the correct name for it

[Anthony]

For some reason, I'm actually having a similar problem this year.  I've done everything it says in the textbook and a few things besides, and still I've not seen the fish properly since the end of April:  To name but a few:

Water Lillies now cover 1/3 surface of the pond.
Water Lettuce/Water Hyacinth another 1/3
Reduced feeding
No restocking after a couple of fatalities
New UV bulbs in both filters
Weekly Filter cleaning
Weekly addition of Clay and Barley Straw
Hornwort occupying large sections of the pond.
Water fleas added on numerous occasions (Read somewhere that they eat algae)

The irony of it all is, is that my top pond which is now unfiltered, gets much more sunlight has none of the plants mentioned above growing it and also has a higher density of fish per litre is perfectly clear - How strange?