BV, not sure why you're hearing air, perhaps it was just the water level
equalizing in the pipe after the pump was turned off? Regarding your
drawing though, how are you aerating your pond? Most of us have our returns
above water level, if not flowing down streams and waterfalls. ~ jan


On Mon, 2 Jun 2003 13:49:23 -0400, "BenignVanilla"
m wrote:

Something occurred to me yesterday. The return pipe from my VF sits at an
angle, and the VF end is above the water level of the main pond. The pond
end is about 8 inches below the water line. The output of the pump is
stepped up to 4 inch, so it is essentially a sealed pipe, in that no water
can enter the pipe from the VF unless it is pumped there. This means that
there is actually an air space in the pipe. The water is pumped in, and
flows down in to the pond.

You can see a crude drawing at:
http://www.darofamily.com/jeff/links...d/airspace.gif

I disconnected the pump the other day, so I could empty the VF and I could
hear air escape from the 4 inch pipe. Hearing the air escape made me thing
there was some pressure in the pipe. Could my pump be working against this?
Should I put a T fitting in and let some of this escape?


See my ponds and filter design:
http://users.owt.com/jjspond/

~Keep 'em Wet!~
Tri-Cities WA Zone 7a
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