"Paul in Redland" wrote in message
...
If you have any idea of the size that of your pond will be, (ball park
idea)
figure out approximate gallons. You should run about 1/2 of your pond
volume
through the filter per hour. That will give you an approximate flow rate,
then go to
http://www.geocities.com/researchtri.../hydrodyn.html
to get an idea of the pipe size that should be used for that flow rate.
Hope
this helps.
Paul

Thanks!