"John" wrote ...

Thanks for all your help.
I obviously messed up on this one and feel responsible for the fish
deaths. It was the hot weather that encoraged me to mess about in the
pond and, I thought, sort it out while cooling down. Yes, it is a
shallow pond. I've moved the survivors to a smaller pond, where they
are a bot crowded, so I need to get them back as soon as possible.
Obviously you don't know the extent of the damage, but can anyone give
a ball park figure of how many days I should wait? Or should I go the
whole hog now and clean the whole pond out? I had thought that the
gunge at the bottom was helping to root the plants. Wrong again I
suppose?


All ponds and lakes are trying to achieve one thing, to fill themselves in.
If you don't clear them out they will achieve their aim. It's why so many
ponds in this country have and are becoming bogs with no depth to speak of.
In years of old when summer reduced the water level they would have a gang
of men clearing them of the mud but it never happens these days and it would
be much easier with all the mechanical means we have.

Personally if you have moved the fish I would do a thorough cleanout. Clear
all the pond plants out and repot them in large ordinary pots with the
drainage holes mostly blocked so the soil cannot come out of them but so
that water can flow a little.
Pond plants do not need drainage holes so why do they sell them in baskets
which they then line to stop the soil washing away? Crazy!
Then refill with tap water and wait a few days for everything to settle down
before returning the fish, with some means of agitation of the water you
could save some time here. Return a couple of fish and wait to see what
happens for a day then if all's well the rest can follow.

Do think about some means of mechanically increasing the oxygen content of
your pond water, pump/filter or just air-pump/airstone. It always helps in
hot sticky weather.

--
Regards
Bob Hobden
17mls W. of London.UK