On Thu, 15 Mar 2007 04:49:45 GMT, wrote:

out how much surface area 5/8 inside diameter x 100 feet would have?

5/8"=.625" 100'=1200" 1sq ft= 144sq in.
..625x3.1416=1.9635x1200=2356.2"divided by 144=
16.3625square feet of inside surface area.

Some time ago someone else mentioned the idea of using a radiator type
network of underground plumbing to filter a pond. He never mentioned
winter or hanging the tube in the sun. Interesting idea.

I know of one person who has a trickle down filter and he says they
work, and even believes they are an improvement over a common flow
through filter, but his latest pond has two Nexus filters like this:

http://www.koivillage.com/filtration/nexus.html

I can't afford one, but I like the idea and am thinking about
experimenting with an air pump, when I can steal some of my wife's
jewelry money to buy it.

Regards,

Hal