I would not do a complete water change, maybe about one third of the water, do not scrub the liner down, that is go algae growing on the liner. Watch what happens after you install the new filter.
"Robert" wrote in message oups.com...
I just ordered a larger better filter for my pond, and I was woundering
if i should remove all the water in my pond scrub it down and clean it
out and refill it with freash water? The only problem is that I have 10
koi in there. Would this complete water change kill them or afect them
in any way?