They will get used to it. When you turn it off, then you will see them
huddle up and hide. The usual background noise is missing.

I see this in my indoor fish tanks (120's) when I turn the filters off for
water changes and maintenance every week. When I turn the filters back on,
they come back out.

Mike

RichToyBox wrote in message
news:xZ0pa.561599$L1.163982@sccrnsc02...
The sound and current will not bother the fish. They will probably like
the
current, and it will give them a little extra exercise. Typically the
recommended pump size is sufficient to turn over the pond in less than 4
hours. My first two preformed puddles were turned over about 3 times an
hour, and your pump will do yours in about 15 minutes.
--
RichToyBox
http://www.geocities.com/richtoybox/pondintro.html


"BruJu" wrote in message
...
Small pond (125 gallons) with smaller pond (35 gallons) that flows into
the
bigger pond as a waterfall. I have a 600 gph pump that flows into a
small
bio filter. Will the sound and action of the pump, run 24 hours a day
drive
the fish crazy? Or otherwise irritate them?