The clay pots are probably not the problem, since most are terra cotta or
similar fired clay. The fish produce waste in the form of ammonia, which is
very toxic to the fish. The filter, if you have one, converts the ammonia
to nitrites, which are also toxic. The filter then converts the nitrites to
nitrates, which are plant fertilizer, but in high quantities is mildly toxic
to the fish. The water changes remove the high levels of nitrates if there
is not sufficient plant matter to consume it. There are also pheromones
which are growth suppressors, signals for spawning, signals for fear, that
can build up in the water and cause the fish to act strange. Water changes
are good.
--
RichToyBox
http://www.geocities.com/richtoybox/pondintro.html


"manzara" wrote in message
news
hello,

I have an indoor pond approximetly 5 months old...water chemistry is
perfect. Recently my shubunkins and koi starting acting strange (crowding
together, skiddish). A pond expert reccomended a medication for parasites
and water changes. Both the medicine and water changes worked
wonders...however it is now going on a week and I am beginning to think it
is more the water changes that are helping and not so much the medicine.
Long story short...are clay pots toxic in ponds i.e. could they be
leaching something bad into the water? Perhaps this is why the water
changes help so much?

Thanks,
Leslie