Some thoughts as you haven't given any details of your set-up or maintenance regime.
a/ Have you introduced new fish recently ?
b/ Is your filter set up sufficient for your pond size & fish loading ?
c/ Do you have sufficient air going into the system ?
d/ Could you have some contamination going into the water ?
eg Metals, chemicals, garden run-off, acid rain, lime from concrete/stones etc etc ?
e/ Do you do regular partial water changes with dechlorinated water & flush your filter ?
f/ Is the fish health problem recent or a long term thing ?
Dosing your pond with all those chemicals may have made things worse if the fish are
already having problems if you did not do a scrape and check for parisites under a microscope.
Good Luck
Posted on Jun 19, 2009, 10:45 AM from IP address 81.137.222.103