I've Googled but can't find anything specific so does anyone know if
salt at up to 0.3% will harm tadpoles?

We have been fighting something since last year and nothing much seems
to help.

It's a 700US gallon pond and had 25 goldfish, up to about 6inches long,
and a large green tench. During last summer they started to get
semicircular wounds on their bodies and one had it's face eaten away.
We assumed it was a large dragonfly nymph. We treated the pond with
antibacterial medication and it cleared things up until the next time.

At the beginning of October we emptied the pond to try and find this
nymph. We cleaned the pond totally and sieved the sediment but didn't
find anything. There wasn't a trace of the usual pond life which we
found surprising. We repotted all of the plants after washing them so
we were starting off with what was effectively a new pond.

Unfortunately the summer ended then and with the temperature now lowish
the fish weren't healing well. We put a 3kw immersion heater in to warm
things up, it was inside a water jacket to prevent the copper from the
element getting into the pond water and we bought a copper test kit to
make sure, we didn't have any measurable amount of copper. The fish
healed although some of the bad ones didn't make it.

Once we stopped the heating it came back again. In February we heated
it to 18C again and PP'd the pond and again things cleared up. Once we
stopped heating there were signs of it returning but the weather was
warming up and as the temperature rose they healed.

We have had a cold spell recently and it has come back again so we are
going to try salt now which is why I'm asking about the tadpoles.

Water is crystal clear. Ammonia, nitrite and nitrate are not
measurable. GH is between 10 and 16, KH 10 and PH 7.2. Filtration is a
Fish Mate 15000 (3000 in the US) pressurised filter with 50l of Kaldnes
media in the bio tank. We had a lot of string algae in the stream but
we always get that in the spring and it clears up once the plants get
going.

Whatever this is it's active when the water temperature drops. The
wounds on the fish are like ulcers and sometimes they get fungus on the
wounds, but that's only to be expected. All fresh water is treated with
Interpet Fresh Start.

We are in North Yorkshire, UK and any suggestions would be very welcome
at this stage. We've lost about half the goldfish now but don't want to
replace them until this has been cleared up. I doubt if we will get any
replacements this year since things are warming up and we need to go
through another winter to be certain it's really gone.


Regards - Rodney Pont email: ngpsm4 (at) infohitsystems (dot) ltd (dot) uk

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posted from HTMl frontend