Nedra is right.
The digestive system of fish start to slow down at about 54 deg. (I wish
my dogs could do that) Fish can pick up any supplimental foods from the
pond bottom.
I remove the pumps, filters, and above ground plumbing before the first
big freeze. It gives me the chance to do a real good cleaning and
recondition.

I gave up on stock heaters. (they last about a year and cost too much)
I went to Walmart and bought a $9 air bubbler w/ bubble stone, an $8
indoor/oudoor digital thermomiter, and a 2 quart lockable food storage
bowl.
I weighted the container inside with a brick. (this also keeps the pump
up high if water does get in)
I also weighted down the bubble stones, they like to float. Any holes can
be sealed with silicon sealant or 'shoe goop'

This setup is on it's third winter. The ice was nearly 8" thick last
winter and I didn't have to open a breathing hole.
Hope this helps.

=================================


"tony" wrote in news:1102333719.241030.25870
@z14g2000cwz.googlegroups.com:

Greetings all,
i have a 2500 gallon backyard pond here on Long Island, New york. It
is starting to get around freezing here now. When should i disconnect
my submersible pump and dump out the biofilter, etc...? Is it too soon?
Have a Laguna WG 10,000 pump and a Laguna 4500 pond filter. Also should
i stop feeding now. Have about twelve 9 inch koi.

Thanks,
Tony