"Klara" wrote in message
In message MadCow writes
In message "
writes

I was about to post that Kay and you did it for me! We are careful
where we buy our watercress from, locally, because Edward (mine that
is, not your Edward) remembered from his student days, someone who got
liver fluke through eating w.cress from a stream in Oxfordshire.


Liver fluke require both sheep and snails (and you to eat a tiny snail
with your watercress) so if you start with safe commercial watercress and
there are no sheep near your pond you should be OK.

What about birds bathing in and defecating into the water, though (as they
do in our tiny pond)? Could that become a problem, even if it isn't now?
Or is washing enough to take care of that?

Bird poo isn't a problem as far as I've ever heard. It's mostly phosphate.
In common with most rural Australians, I use only rainwater collected from
the roof for drinking and showering purposes and we have lots of birds in
our garden. I doubt whether they are so considerate that they don't poo on
my roof where the rain falls.