Pat wrote:
Try here
http://www.happykoi.co.za/1.%20all%2...filtration.htm

or here http://www.hendersons.co.uk/filtration/page2.html

or here
http://www.koi.com.my/forum/KOI_Talk...Urgent!_P2381/

Don't think I would use a swimming pool sand filter but if you must try one
I would use it last just before you return the water to the pond.

Brushes work well as a coarse filter after the settlement basin. Then a
veggie filter.

Thank you.

Ques 1: The 1st article says use a mechanical filter before a sand
filter. That is exactly what I am planning. There is a plastic basket
that has fairly small 1/8" slots that all the water from the drains and
skimmer go through before my sand filter. This is easily cleaned.

Ques 2: Why not a sand filter w/backwash? BTW, I am converting a
swimming pool into a pond w/ swimming "hole". I would like to use as
much of the current plumbing and filter set-up as possible.

Ques 3: I read that the veggie filter should be the last thing before
re-entering the pond?

Ques 4: These articles don't address what a "settlement tank" is. My
original question.

Chip