Thanks. I should have mentioned that the pond is about 1000 gallons,
18-22" deep. This will be its first winter...just installed it in
June.

Phyllis and Jim Hurley wrote:

The running water will cool your pond to freezing rapidly. That is not a
problem for the fish. If your pond is small enough to freeze entirely, your
flow will speed that up. The earth is a warming agent if your pond is deep
enough.

The ice is no problem as long as it does not block your flow and empty the
pond. That is your biggest danger. Has the pond frozen over in past years?
Your neighbor's experience is a better guide than my experience here in
Jackson, MS.

The lettuce and hyacinth will die in the frost. The lettuce will simply
disintegrate once it dies. We used to pull it as soon as a bunch of it got
frozen. The hyacinth can survive winters if the growth bud is not frozen
solid. We tent the hyacinth in the berm ponds for the winter and strip out
the dead matter in the spring. About half of them make it through the
winter.

Good luck.

Jim


"Dan" wrote in message
...

I live in zone 7 (MD) and was toying with the idea of leaving
the waterfall running all winter. My brother-in-law has done
so for the last two years with no apparent ill-effects. Whenenver
the pump shuts off, the water drains out of the lines (all run
down hill) so I'm not sure a power outage would have a major
impact and i think my waterfall edges are high enough to keep
water from changing course as ice forms. Is there anything else
to be concerned with? Would that be good or bad for the fish?

Also, when should I dispose of the water lettuce and hyacinths?
They seem to be doing fine right now. Water temp is around 55
degrees and we've had a few very light frosts so far. Thanks!