Ulcers are a sign that something is breaking through the slime coat of the
fish and allowing in bacteria. It could be from scraping themselves on
rocks, but most likely it is parasites. The use of KoiZyme (previously
Limnozyme) will help reduce the number of pathogenic bacteria, but will not
reduce the number of parasites. If you can, take one of the fish to a good
pet store that has a microscope and someone that knows what to do with it,
or contact a koi club in your are and see if they have a person familiar
with the microscope that can diagnose which parasites you have. Once you
know, then you can work on a remedy for the parasites.
--
RichToyBox
http://www.geocities.com/richtoybox/pondintro.html


"Smith" wrote in message
...
We moved in last year, and there was a pond (in the garden, complete with
liner, but no water. We filled it, (it's 3750 litres - is this medium or
large?) and left it for about 2 weeks then introduced plants.

We then added 15 goldfish and a pond pump. The fish seemed OK - we lost
one
to ulcers over the last summer. Frogs, newts, snails and water boatmen all
took up residence, so we assumed we had created a good habitat.

However, from September to March, we lost 3 fish to ulcers. I did ulcer
treatments after we lost the first one, but it didn't seen to do much
good,
so I did it again, then we lost 2 more.

In March, I salted the pond (1% dilution) and everything seemed OK for a
little while, so we got 10 more fish, making the total 21.

But since then, we have lost 6 fish in quick sucession. Some we can see
had
ulcers, but 2 of them didn't have a mark on them. Today I can see that
there
are 2 with ulcers that aren't going to survive for long, and one of those
is
one of the new ones. I checked the new ones over before I put them in the
pond, and they had no signs of disease, so I can only assume it's the
pond.

I feel awful, as I feel I'm just putting fish in there, and condemning
them
to death. I have put a Medipad in yesterday, to see if that will help, but
I
don't know what else to do. The pond is reasonably clear, and all the
other
wildlife is surviving, indeed the snails and frogs bred this year.

Any advice would be gratefully appreciated. I thought goldfish were
reasonably low maintenance, compared to Koi, and that they were more
tolerant of fluctuations in condition. If they keep dying, I'm just going
to
have to have a pond without fish, because I don't feel like putting any
more
in there, just for them to die.

Sadly yours
Tracey