Hi Group,
Using a natural method, sprays or water changing only compound the problem.
I assume that you have no fish or livestock in it at present.
Firstly;
Acquire some daphnia (water fleas) these are sometimes available from "good"
tropical fish shops, but are easily obtained from a small pond or ditch that
would dry from time to time. You remember the little old fishing net you
used to get as a kid, a length of bamboo with a loop of wire at the top
with a bit of net on it. Well, make something like that but a bit stronger,
for the net part use a bit of the wife's stocking.
Find a suitable container with a waterproof top and off you go searching the
countryside for suitable ponds and ditches, (when you find one don't go
shouting about it, they are valuable, there's good money to be had supplying
tropical fish shops). Anyway transfer a load live into your pond and leave
alone for a couple of months, and they will clean your pond. The daphnia
have a short lifespan but don't worry they will leave their eggs in the pond
for the future. Try googling daphnia, there's a lot of info there about
them.

Secondly:
Get some pond weed and let it establish, the roots of the pond weed will
also draw the smelly nutrients out of the sludge that has acquired, you will
also need a few water snails to keep your weed clean and active. Don't
forget to add a lily or two depending on the size of the pond, natural shade
is necessary.

Thirdly:
Having made your pond nice and clean you need to add some fish, who will be
delighted with you, because you have provided them with a menu of daphnia
and water snails, try a few native fish like tench and rudd.

Result;
A nice pond that is a pleasure to look at and is a source of natural refuge
for many other species i.e.., frogs, newts etc.
Warning;
Keep your eyes open for herons, they will destroy your fish life in less
than an hour on a small pond.

Best of luck
David.





"Tulpa" wrote in message
oups.com...
Hi all,
Is it me or are all non filtered ponds prone to get smelly without the
benefit of growth and sunlight? I'm hoping all will come good when the
UV starts filtering through. Otherwise, I'm looking at draining with a
bucket and replacing all the hard work of last year!
Any ideas?