I just recently installed the Calpump 4000. I think it is good unit for the
price.
The model 4000 is advertised as having 1 1/2" male NPT inlet & outlet, but
it actually has 1" threaded connection points with an adaptor to 1 1/2", so
you will need a pump with some pretty decent pressure ratings in order to
get maximum flow through those smaller fittings.
It comes with 6 sponge inserts, 2 each of very fine, medium & coarse. Also
included are some bioballs. I added some very coarse filter mat at the top
of the unit.
The backflush feature does not work very well. There is to much restriction
from the small backwash exit port, which does not allow a large flow of
water while in backflush mode.
I think it is a good addition to my filtration sytem, but I would not want
to rely on it as the only filter on my pond, which is similarly sized to
yours.
David

"crclark" wrote in message
thlink.net...
Hi, to the all knowing and most trusted ponders...Has anyone tried a
Calpump
Pressure Bio Filter?? I am in need of a filter I can clean without
calling
my daughter and getting into the pond and lifting out a 2T rolled filter
w/pump...(ton maybe exaggerated) but very heavy. We then wash it, re-roll
it and it is good for maybe another week. My water is crystal clear, but
cleaning the darn thing is really a pain..Fish and plants are healthy so
maybe I should just quit whining. My pond is 23'x18'x2 and holds close to
a
1000 gal. I am still working on getting the gunk off of the bottom. What
does anyone think??? I have always appreciated your help in the past
years
and would never have know a lily from and iris had it not been for this
group..Thanks
Connie, Idaho