Hi folks,

I need some help with planning for a new pond.
I am building a 6 x 15 kidney shaped fish pond and was going to fabricate a
biofilter in a large drum.
This would follow the many DIY plans available ...
I was going to hide it inside a 1.25 meter waterfall....complete with access
from the back and plumbing to reverse flush clean the filter....

However, a friend of mine who has had a pond for many years has suggested a
stream with a few deep pools separated by two waterfalls.
He tells me these are capable biofilters, I believe that is what he has, and
it's a new option for me as you can't do that in aquariums...

I am a seasoned aquarist with both Salt and Fresh water aquariums.
So the usual idea of mechanical, chemical and then biological filtration is
standard operating procedure for me.
For the pond I had chosen a skimmer and pail with a net plus a filter in
front of the pump as mechanical filtration.
I was planning on following it with a UV lamp, and then the drum biofilter /
waterfall....

My questions are these:
Is a stream, which I have room for, as good as a crushed gravel 40-gal drum
for a biofilter?
Will the stream require draining and flushing periodically like I had
planned for my drum filter?
If so what is the typical interval and process?

Thanks for any help and suggestions you can provide !
Joe Ficalora