"George" writes:

wrote in message ...
Cleaned the "Gunk" from the bottom of my koi pond the first time in 10
years. This pond had twelve 10 year old koi that were very large. I
decided to sell them and keep goldfish and plants again. I never..I repeat
never felt the need to clean the gunk. It is an outdoor pond and not an
aquarium. I have a very good filtration system and only cleaned a 5 gallon
bucket of "gunk" out of the pond. {:O) MIKE

I'm like you. While my koi are still young (about 2 years old), I have a large
albino channel catfish and a lot of goldfish. My pond is only a year old, but
even being located beneath a very large pin oak, where leaves and acorns
regularly fall into it ( I do screen the pond in the fall), the bottom of my
pond is perfectly visible. No gunk at all, not even an acorn. The bacteria I
use digests the debris completely

Me too but I don't use a bacteria additive, I do have a settling chamber
in the filter. I've often wondered why some get a build up and some do not.
I do have maybe half an inch of black aquarium gravel in mine that the koi
root around in, maybe that keeps stuff stirred up until it drifts into the filter?