I would need lots more information before guiding you on
this. For Instance, Is the bottom
just dirty? How many gallons are you talking? How big and
how old are the koi?
I would wait until the cooler temps of autumn before attempting
to clean. Please get back to us on these questions ......

Nedra
http://www.geocities.com/Heartland/Pines/4836
http://community.webshots.com/user/nedra118
"David Appleby" wrote in message
...
when is the best time to completely empty the pond and refill it,I have a
koi pond.