Lynda,

oxygenators usually sit on the bottom most of the time, so shouldn't compete
with surface plants.

From Google -

Lagarosiphon major
from page
http://www.bbc.co.uk/gardening/htbg2..._plants2.shtml
or
http://tinyurl.com/g8ec

Our somewhat larger pond has this, along with lillys, irises and water
hawthorn.

It sits on the bottom in winter, and then grows in summer.

You may have to wait awhile for your pond to achieve balance; if it is going
stagnant this suggests that there is too much organic material in it at the
moment.

Growing an oxygenator then removing some is one way to reduce the organic
content of the water :-)

HTH
Dave R

"Lynda Thornton" wrote in message
...
In article , David W.E. Roberts
writes

"Lynda Thornton" wrote in message
...
Hi

The water in my barrel pond where I have a water lily has got an
unpleasant oily sheen - I think it might be going stagnant. Is there a
chemical I can add to the water to get rid of this? I don't have room
for more plants to oxygenate the water so I wanted to try and find
something I could add to the water to get rid of this film.

Thanks.
--
Lynda Thornton

Lynda,

I am prety sure that there is room for one little oxygenator.
Pet shops sell little bunches for the tiny bowls some people keep
goldfish
in.
If your pond is unhealthy - not maintaining itself naturally - then
blitzing
it with chemicals is not going to make it better.
If you go the 'chemicals' route you will have to repeat the treatment at
regular intervals - you are tackling the symptoms not the disease.

I would suggest that you add one small oxygenator and commit to removing
any
excess growth once a month (or less frequently if the pond looks O.K.)
and
adding this to your borders or compost heap.

This is likely to keep your pond much more healthy, be more
environmentally
friendly, and cost less and take less efforts than repeated chemical
treatment.

HTH
Dave R


Hi David

The problem is that I've already got a water hawthorn in there as well
as the water lily and also 2 irises in a basket nearer to the surface,
so there really isn't that much surface left for another plant to fill,
and I wouldn't want anything to swamp over the other plants and cover
them or inhibit their growth.

Is it possible that oils from the barrel (oak) or its old contents (I
assume some kind of alcohol or spirits) could be leaching into the
water, or is this a known feature of stagnation? The barrel was cut in
half specifically for me, it hadn't been open to the elements or used
for water before I got it.

I quite agree with the environmental approach and usually try and avoid
chemicals as a rule - I wonder if there is any environmentally friendly
additive I could use. If I did go down the oxygenator route, would it
have to be a prolific plant to clear the water quickly or what? Can you
recommend a particular one for a 3' diameter barrel that won't
immediately go mad and invade the whole thing?

Thanks for your help so far!
--
Lynda Thornton