"Steve" wrote in message
Hello,
I have a garden pond in the UK, about 20 ft x 15 ft. The pond has
no
pump, but lots of plants (and blanket weed)
but the water is generally v clear & seems healthy.

A few days ago, I noticed a dead goldfish floating on the surface. There
were no obvious signs of injury / disease.

It is obviously your ambition to create a natural pond, however, due to the
abnormal weather through march and april, wild life has thrived to early,
although your plants are looking good, you must remember we have still had
the long dark nights, where no plants give off oxygen, this over such a
period of time, creates a static impure bog.
admittedly if your pond is in a very windy position, you do have surface
movement, if not, you will have many problems.

This is not the environment for any member of the carp family, in these
conditions,they will suffer from mouth
fungus, and parasites, plus many more diseases, you have to form some
circulation that can spray and
mix oxygen into the water, to rid your pond of impurities, if you do not
intend to fit any filtration.

Neither the original, dead fish, or any of the others now in the pond
displayed any of these signs.

Assuming your pond is 2ft deep, this is quite a large pond, that has taken
time to deteriorate

Am I worrying unnecessarily, or does it look like there's something nasty
going on?

Yes, without wanting to upset you, the answer is neglect, there are many
natural farm land static ponds in the country side, some smell, some don't,
but non of
them have carps.

NB although I have few fish, the pond is essentially given over to frogs,
dragonflies etc so I'm reluctant to treat the water with anything which
might adversely affect the wildlife

Remove the blanket weed, and all the very black mess at the base of the
pond, you will have to be a little ruthless at this point, carefully bathe
any sick fish, with a little salt, to remove any fungus.
I, for one, never use any chemicals, a little rock salt and good
circulation.
Please remember, that touching, a cold water species, is the same as you
placing your hand on a hot plate.


I'd be grateful for any advice - thanks

My pleasure