I left the waterfall run like I have every year since I put it in and have
had no problems before with winter kill. When I cleaned out the pond in late
Aug/early Sept there were 45 fish. Out of the 45 perhaps 25 of them were 1"
or less, ten of them were 1.5" long, 10 of them were 2" long, the other 5
are at least 4". Out of all that the fish that have survived 4 are the
bigger ones with the exception of perhaps 3 or 4 smaller ones (1") The three
biggest ones that are left have been in the pond since the first year. One
note on the whole discussion about water temps. The filter sits up one
level from the absolute bottom. In other words it sits up about 8" from
bottom. The filter has sat here since day one also.
"kathy" wrote in message
ups.com...
Fish health is not my area but...
- did you do anything different this year than
the previous winters?
Such as a fall clean out, the waterfall running during
the winter. That would probably be where to start looking.

One year I went into winter with a huge growth of anacharis
in the pond, so much that sometimes I could never see the fish. By
winters end it was all gone! I was sure surprised, and I assumed the
fish (a lot of koi at the time) chowed down on it sometime during that
period.

Also your fish have probably mulitplied in the time you've
had them. What may have worked for the orginal fish load
may not be working for the current fish load.

kathy :-)