Question
LAST WEEK I TURNED ON MY FILTER AND PUMP AND STARTED TO CLEAN MY POND. A DAY LATER AS THE WATER HAD CLEARED I NOTICED A DEAD FISH KOI ON THE BOTTOM ,IS THIS COMMON OVER THE WINTER PERIOD. I'VE BEEN TOLD TO ADD START ADDING SALT IN THE POND TO KILL OFF ANY PARASITES SHOULD .

Answer
Hi Jonathan,

De fish could have died because of different reasons.
So we have to cold water, sickness etc..
Salt adding in the ponds is commonly seen, and correct it can reduce parasites.
However not all and if koi are in low resistance due to the winter the effect can be the opposite.
Best way is to let the filter run (slowly) in the winter and refresh some water after the winter.
Also adding bacteria for start-up is advised.
If there is only one fish, than I think you just need to monitor the entire population and when special behavior is noticeable, check for parasites and other problems and act accordingly.
Hopefully this helps.

Kind regards,
Raf