Okay here are some answers to your questions but first I took some pictures.
Here is the link http://s7.photobucket.com/albums/y264/Nikkiekoala/Pond/

For Jan yes we have taken apart the filter, removed the charcoal bags and
shot the hose thru' the top flex pipe that goes to the pump. The water went
thru' but not sure how well.
The water didn't back up into the filter when spraying in. Doesn't mean
anything though. Obviously the water can flow thru' whatever is there if
something is in there.

The pipe in the pond to the pump is definitely larger than the pipe that it
joins with that then goes to the filter. So something maybe in the larger
pipe but is too big
to pass thru' to the smaller pipe. The flexible pipe at the lid of the
filter has sprung a leak, that is the pipe that goes out to the pump. In the
pictures you can see the
pump box and under the box you see the flex pipe come out under going into
the ground. We are probably going to have to replace this flexible pipe. The
leak is a
pin hole leak too small, I think, to affect the water pressure that much.

The filter has a gauge on the lid on the opposite side from the water
intake. The water out up to the waterfall is on the bottom. It is the gauge
that measures psi in the filter.

My thinking is this....The clog or problem has to be between the pump and
filter. If the problem was after the filter the psi in the filter would
still read 5psi maybe higher if there
was a slow down/back up to the filter. Since the filter is not showing 5psi
with water coming in something is obstructing the water flow before water
enters the filter. Right?

Since moving rocks, cleaning filter, back flushing filter to pump pipe
yesterday we went from less the 2 psi (resulting into a trickle at the
waterfall) to 3psi (resulting in a much faster water flow
from the waterfall but less than what is normal) in the filter so something
we did improved things but didn't complete fix it.

Boy, this thing has my brain going all the time. I can't wait until we get
to the bottom of it all. Hubby is working today so I am not sure it he is
going to want to deal with it today. I think
I may unearth the flex pipe down to the pond edge and see how the smaller
pipe and larger pipe is joined.

Thanks so much for helping us brainstorm this. BTW any of you around the
Portland Oregon area and would like to play in our pond *wink*

"Phyllis and Jim" wrote in message
oups.com...
Intersting point. I am curious about how the pressure is measured.

You commented on 3 psi -through- the filter. Does that mean into
rather than out of? Can you tell about the into and out of pressures?

Reflectint on your system: You have mentioned three main components:

Pump: plumbed in and hard to move. Seems clear of debris and has free
impeller. Water flow into the pump appears free. The system was
working with this arrangement. Supposed to handle up to 2" junk. If
junk through is larger than the outlet and is fairly solid, it could
clog the pump at the outlet and restrict the flow.

Pipe: 5-6 ft long. Not yet clear if it is plugged in some way. If it
is smaller than what the pump can send on, i.e. less than the exit of
the pump, it could be plugged by the pump. I suspect the pump,
however, has a smaller outlet than 2". Perhaps the pipe could be
snaked or have an hose pushed into it to flush it. If it has turns
and if something came out of the pump that could not clear the turn,
you could have a problem that you would not find.

Filter: Easiest to clean or to inspect. I gather you can check out
the pressure in some way and perhaps make a visual inspection. Would
a clog or jam show up? Could you recognize it?

Interesting and painful problem. I suspect lots of us would like to
jump into your pond!

Have I missed any components?

Jim